Method and device for the efficient use of long-acting adhesive in the factory and during personal use

ABSTRACT

The invention relates to a method of producing a product comprising a support having a long-acting adhesive and a protective tape disposed thereon, so that said adhesive can be used at a later time. The inventive method is characterised in that it consists in: determining a reference plane (P) which is close to the location of the adhesive deposit and which is either below the plane containing the lower face of the support or above the plane containing the upper face of said support; establishing the distance (D) separating the reference plane (P) and the level (N) at which the adhesive ( 2 ) is delivered, which is close to the plane containing the application face of the support; delivering the long-acting adhesive ( 2 ); delivering a protective tape ( 20 ) which is disposed on top of the adhesive ( 2 ) either simultaneously using a prefabricated transfer tape or separately; moving the support in relation to the deposit station; exerting a transverse force on the support such that one of the faces thereof is applied continuously against the reference plane (P); and exerting a pressure, counter to the transverse force, on the protective tape ( 20 ) and the adhesive ( 2 ).

This application is a 371 of PCT/FR03/00551, filed Feb. 19, 2003.

The present invention relates to the application of long-acting adhesiveto products made of compact cardboard, corrugated cardboard or similarmaterial.

In the following description, reference will essentially be made tocardboard (compact or corrugated), but solely for reasons of simplicity,the invention in no way being limited only to this material.

Likewise, with reference to most current adhesives, it is noted thatthey are often used by heating so as to make them malleable, but it mustbe understood that the important thing is to apply a long-actingadhesive, whether it be applied hot or not. There are known, forexample, long-acting adhesives of the mastic type which extrude verywell cold and which adhere to the supports to which they are applied, byvirtue of a pressure that is exerted on them, the invention thusrelating to any adhesive that is sufficiently malleable to be appliedhot or cold.

Adhesives have reached an excellent degree of efficiency and they aregenerally tending to replace other means of assembly.

The invention applies in particular to the manufacture of panels andpreforms intended to create containers designed for dispatch by post orby parcel service, but also relates to any type of application whichrequires the presence of an adhesive that is to be used a long timeafter it has been applied.

It is known that only an adhesive makes it possible to join two elementssuch that they are inviolable, in particular to close and keep thevolume of a container obtained by folding a previously cut and groovedpreform.

This is particularly the case for containers delivered flat in the formof preforms that are sometimes partially preassembled, and which usersuse one by one (and of course manually) to place therein articles thatare to be dispatched. Following closure, it is necessary to avoidaccidental opening of the container during handling and transportthereof.

A closure known as a “security closure” must be very strong to withstanda maximum force but, with respect to cardboard, it is obvious that thematerial in itself is not robust enough to prevent fraudulent or simplyaccidental access. In reality, it is necessary that any abnormalopening, carried out without the permission of the addressee, should bevisible.

The general problem of fixing by means of an adhesive can be dividedinto two families: immediate bonding using glue and delayed fixing usingan adhesive.

The present invention does not relate to gluing but rather to the secondfamily which groups together all the cases where it is necessary firstlyto deposit a long-acting adhesive (and not a glue) on a part, orelement, of a support, then to store the support coated with adhesive,which is not to be used until later, sometimes a very long timefollowing application, to join this first element to a second element,which is often another part of the same product: cardboard sheet, panelor preform for example.

The place where the adhesive is deposited in the factory is known as the“application surface” and the place where a second element is to bebrought into contact with said adhesive is known as the “destinationsurface”, this latter operation usually consisting in closing acontainer, such as a box, for the purpose of sending articles placed insaid container by post or parcel service.

This closing operation takes place after all types of events have takenplace: printing, shaping, storage, packaging, transport, delivery,storage again, removal from storage when required, various handlingoperations, etc.

The technique of immediate gluing has become relatively simple since,ultimately, it is now reduced to selecting a family of glues and, wherenecessary, adapting the selected glue to the problem posed, by adjustingits composition and/or its setting time, since two elements are fixed atthe same time and there is no longer any need to distinguish between anapplication surface and a destination surface since their mutual gluingis simultaneous.

By contrast, delayed use of adhesive is much more complex since highlyvaried requirements have to be met, these stemming from the existence ofthree separate situations instead of just one:

-   -   deposition of adhesive at high speed, in the factory, onto the        application surface of a given support,    -   resistance of the adhesive to slow ageing and to physicochemical        and mechanical stresses,    -   instantaneous efficacy of said adhesive on the destination        surface, even a long time after initial deposition on the        application surface.

In this case, it is thus necessary to distinguish between two operationswhich are very different even though they concern the same adhesive:adhesion to the application surface then adhesion to the destinationsurface, the whole having to effectively secure two separate elements.The solutions which currently exist are not entirely satisfactory in allfields of application.

For example, it is quite easy to deposit long-acting adhesives (or“delayed-action” adhesives) on supports formed of materials that have aneven surface and/or excellent planarity.

This is the case in respect of the paper used to produce envelopes inparticular, since during deposition of the adhesive the paper is placedon a rigid and flat bearing structure, such as a steel plate, so thatits thinness allows it to adapt to this bearing structure and take onthe characteristics thereof. Ultimately, if the paper is correctlyguided and held, it behaves as though it were itself rigid and hard.

This is also the case in respect of materials which naturally offerthese characteristics: compact cardboard, glass, synthetic materials andsmooth metals.

Assuming that the adhesive is securely associated with the support, thesubsequent fixing to the destination surface is still not ensured sinceit is still necessary that the qualities of the adhesive are retainedover time and that there is a compatible destination surface. Hereagain, the case of a sheet of paper is relatively simple since, becauseit is both thin and flexible, the destination surface will joinperfectly with the adhesive.

In these favorable cases, the only problem to be solved is that ofmasking the adhesive so that it does not accidentally adhere to otherobjects and so as to protect it against collecting dust and againstageing (drying, oxidation, etc.).

The solution adopted consists in placing on the adhesive, which hasalready been applied, a protective tape which is associated withsilicones so that it adheres very little to the adhesive, thisprotective tape being removed only at the time of final use, that is tosay when it is desired to apply the unmasked adhesive to the destinationsurface, so that the latter is joined to the application surface, inparticular so as to keep fixed together two parts of one and the samepreform forming a container such as a box for dispatching articles bypost or parcel service.

On the other hand, long-acting adhesives are poorly suited to materialswhich are not thin.

In order to attempt to solve the problem of rapid deposition of adhesiveon an uneven application surface, use is made of “transfer tapes” whichcomprise a thick and flexible plastic film, or “core” or “base”, oneface of which is coated with a first adhesive for the purpose of fixingit to the application surface and the other face of which is coated witha second adhesive suitable for fixing the assembly to the destinationsurface, and covered with a removable protective tape, the base beingassumed to be flexible enough to compensate for the irregularities ofthe support.

Experience shows that the fixing of this transfer tape to theapplication surface is satisfactory but that, by contrast, the fixing ofthe assembly to the destination surface is problematic, or evenineffective, while a transfer tape of this type is expensive.

One characteristic example of a material that is poorly suited to theuse of long-acting adhesive is corrugated cardboard, and it is thelatter which is used here to explain the invention, although saidinvention has many other applications on various materials: wood,compact cardboard, synthetic materials, metals, etc.

In practice, the sheet of corrugated cardboard most frequentlyencountered has two so-called “flat” faces, each formed by a sheet ofpaper and placed on either side of a core having corrugations, orgrooves, these three parts being secured by glue so as to make anassembly that cannot be dissociated. However, when looking carefully atthese faces, it is possible to see, even with the naked eye, fairlypronounced depressions at the hollow grooves, which constituteirregularities that are extremely unfavorable to the use of long-actingadhesive.

The difficulty is relatively small during application in the factorybecause an attempt is made to combine the best conditions forapplication to products that are new, clean and free of dust forexample; however, the difficulty increases considerably when fixing tothe destination surface, for two separate reasons:

-   -   the destination surface might have been damaged or soiled, thus        offering mediocre adhesion power, due to the fact that the        support is transported, stored and left to wait for long periods        possibly of up to several months, under variable conditions in        terms of temperature, hygrometry and purity of the atmosphere,        and is often handled without care;    -   removal of the protective tape and application of the unmasked        adhesive to the destination surface may be carried out        incorrectly by a person who is more or less dexterous and        attentive and/or exerts a manual pressure that is too low to        ensure a strong connection to the destination surface.

Knowing the difficulties which stem from the irregularities ofcorrugated cardboard, an attempt has been made to remedy these bysubjecting the original paper and/or the corrugated cardboard as a wholeto treatments of all kinds aimed at giving the final object a niceappearance and high rigidity, both synonymous with high quality.

Unfortunately, the corollary of these treatments has been to makeineffective the application of adhesive in the factory and above all thesubsequent fixing of said adhesive to the destination surface.

This is because the nice appearance requires a very white and shinysurface, and therefore recourse is had to a surface application orcoating containing for example kaolin or titanium, or forming a varnish,or to the application of printing ink etc., and moreover to the presenceof manufacturing marks which can be detected only under ultravioletlight, these having to be protected by a type of paint.

All these coatings have a barrier effect which consequently fully coversand dissimulates the fibers of the original cardboard, whereas thesenaturally have an excellent adhesive retention power because of the factthat they give the product a porosity which is favorable to theattachment of the adhesive by partial penetration into the porous mass.Smooth and continuous coatings, on the other hand, make the productimpermeable.

The problem is further aggravated by the concern for quality whichforces the professionals to choose a high quality corrugated cardboard,manufactured for example with pure Kraft paper with long fibers orreinforced with a strong glue binder, and which is already in itself anobstacle to the use of adhesive for two different reasons:

-   -   the adhesive does not penetrate into the fibers and attaches        poorly,    -   the user carrying out fixing to the destination surface presses        on a thick, rigid and resistant support, reminiscent of a        material such as wood, so that even by exerting a sufficient        pressure on the upper face, this pressure is only partially        transmitted to the lower face of said support.

This leads it to be explained that experience has shown that effectivefixing to the destination surface depends on the flexibility of thesupport since, by pressing on one face of this relatively soft material,the pressure is easily transmitted to the opposite face and forces thissupport to fit into all the surface irregularities, thus causing anintimate bonding of the adhesive to the miniscule reliefs and hollows ofthe support.

Overall, there is thus a contradiction in that the support should berigid for the adhesive and soft for the closing pressure.

Moreover, one may be led, depending on the specific desired resistance,to give a sheet of corrugated cardboard a complex structure: twocorrugated cores and three flat faces, namely two outer faces and oneinner face separating the two corrugated cores, for example, whichfurther complicates the use of long-acting adhesive.

In order to simplify the description of the present invention, thepresent text will content itself with the case where the sheet ofcorrugated cardboard has just one corrugated core and two so-called“flat” faces.

Following application of the adhesive in the factory, thesupport+adhesive+protective tape assembly is stored, transported, storedagain, handled and then distributed, until actual use of the adhesivewhich is unmasked at the last minute, which use is delayed over timewith respect to the moment at which the adhesive was applied to theapplication surface of the support.

In general, the sheet of corrugated cardboard forms a constituent partof a preform that is to form a container.

It is thus at the moment of closing the container that the adhesive isrequired to join two of the constituent parts thereof, one bearing theapplication surface provided with the adhesive covered with theprotective tape and the other bearing the bare destination surface. Todo this, one end of the protective tape is lifted, this detaching moreeasily from the adhesive than it does from the application surface.Thus, the protective tape can be easily removed to unmask the adhesivein its entirety, the latter remaining secured to the applicationsurface.

On its face that has been unmasked by removing the protective tape, theadhesive is to have retained its adhesive power so as to allow the firstelement of the support to be fixed to another element of the samesupport by means of simple contact. Thus, the two elements are fixed byapplying the element bearing the adhesive to an element which does notcomprise adhesive. However, a transfer tape is quite expensive, both interms of its manufacture and in terms of its placement, and thus this isa solution that must be rejected if the final product, incorporating thecorrugated cardboard support, the adhesive and the protective tape, isto be inexpensive.

The surface irregularities of the corrugated cardboard are sometimes notvery visible to the naked eye and are barely sensitive to touch;nevertheless, they do still exist and greatly impede the use ofadhesive.

This characteristic of corrugated cardboard of having irregularities ismoreover well known to the person skilled in the art since it is notpossible to determine the thickness of a sheet of corrugated cardboardusing a simple apparatus: it is necessary for the parts in contact withthe two faces of the sheet whose thickness is to be measured to have arelatively large surface area so as to compensate for the irregularitiesmentioned here.

For example, French standard NF Q 03-030 specifies that the parts of theapparatus (“keys”) in contact with the sheet must each be ten squarecentimeters (10 cm²).

In “LE COLLAGE INDUSTRIEL [INDUSTRIAL BONDING]” by Phillipe Cognard andFrancoise Pardos, Editions de l'Usine Nouvelle, Paris, page 12, it isstated:

“Actual Contact Surface

Contact between the two surfaces of two solids occurs only at a fewpoints in microscopic terms. If we assume the case of a liquid wetting asolid, there will be microscopic air bubbles which will prevent contact.Therefore, in both cases, the actual contact is less than the proposedcontact and the actual resistance will thus be much less that thetheoretical maximum resistance.

Surface Defects

Given an equal contact surface, an actual surface will provide anadhesion force value that is lower than that which would be provided byan ideal regular surface. This results from the existence of numerousdefects in actual surfaces”.

In order to make a sheet of corrugated cardboard self-adhesive, it isthus necessary first of all for it to have a surface that is as even aspossible and for the tape used to itself be of very good quality, thesefactors being incompatible with a low cost price.

Even with sheets of corrugated cardboard that are manufactured withpapers of high quality, a satisfactory result is not always achieved,even when using transfer tapes with a central base.

A good quality adhesive should attach to the cardboard in a sufficientlystrong manner, in particular by impregnating the surface thereof, sothat removing it even carefully causes an irreparable and obvious tear,in particular by tearing fibers that form the support. Moreover, forreasons of economy but also for ease of application, it is good if theadhesive is present in a small quantity.

Mass production of products made of cardboard, strips, panels orpreforms, requires that the adhesive be applied at rates of travel ofmore than one hundred meters per minute.

When applying the liquid adhesive and a protective tape that covers allthe adhesive to one another and virtually at the same time, theapplication surface on a machine is particularly critical because of theextremely dangerous consequences of the slightest deposition accident,whether this be of the adhesive itself or of the protective tape.

When the adhesive and the protective tape are applied continuously, thatis to say when there is just one support which is of great length, orelse when the support is formed of successive panels but the protectivetape is not cut between the panels, it is enough to start once and forall the fixing of the protective tape at the start of the first panel,so that said protective tape is fixed securely enough to the supportthat the latter can be displaced at great speed while drawing the tapethat is stored in reels and unwinds freely on account of this traction.

On the other hand, when the adhesive and tape are depositedsequentially, that is to say when between each panel the distribution ofadhesive is stopped and the tape is cut, the restarting of deposition afraction of a second later on the next panel once again requires a smallamount of time which is prejudicial to the desired rate. If the speed isincreased, there is a risk of a mistake consisting in having appliedadhesive but no protective tape, which may lead to a very seriousincident since without protection the adhesive may adhere to the partsof the machine and/or to other adjacent panels, and to avoid this themachine would have to be stopped and thus production would have to beinterrupted.

The following documents may be mentioned by way of prior art:

U.S. Pat. No. 4,102,301, which relates exclusively to a coating methodand discloses a solution for manufacturing by this method eitherbarrier-effect films for packaging salt meats, hams, etc. or adhesivetapes for stationary.

The method consists in covering the entire surface of the support thatis to be coated and, to this end, there are firstly a number of stripsof the coating product and then, using a roller common to all thestrips, they are spread so that they meet and form a complete andcontinuous coating over the entire surface of the support.

The support that is to be coated does not comprise any irregularities,quite the contrary since it is a thin extruded sheath made of flattenedsynthetic material.

FR-A-2 331 386, which describes an automatic machine for depositingadhesive drops onto earthenware tiles and crushing them by means of apress-plate, a slightly adhesive sheet being inserted between the dropsand the press-plate.

The solution described does not allude either to the existence ofirregularities of the support or to the fibrous nature of this supportor to the use of a flowing adhesive or to the creation of a continuousbead or to the rolling of this bead in order to level out irregularitiesin the support.

U.S. Pat. No. 3,401,608, which describes a method for applyinginexpensive glue, such as dextrin, to a support that is fibrous butcovered with a product unfavorable to gluing, which consists inscratching the coating in order to make the fibers appear and inapplying the glue directly to these fibers. This therefore relatesexclusively to the deposition of glue, since two parts are fixed at thesame time and this gluing carried out in the factory moreover providesfor the immediate pressing of the two parts one against the other, withthe glue setting within a very short time. There is no applicationsurface and destination surface, nor is there long-acting adhesive madeto act in two steps separated by a long period of time.

With long-acting adhesive, it is virtually impossible to leave barefibers exposed for a long period of time since, besides the fact thatthis would give the product a mediocre appearance, baring of the fibersby scratching makes them hirsute and, at this point of dislocation, along-acting adhesive would not be able to adhere strongly to them anymore so than an adhesive tape could adhere to carpet for example.

U.S. Pat. No. 2,996,238, which is similar to the previous document andrelates to thin paper bags manufactured by longitudinally folding a thinsheet that is folded longitudinally and the margins of which aresuperposed and fixed to one another so as to form a sheath which isclosed on itself. This closure is effected by gluing and, since thelower face of the sheet is applied to the upper face, the two faces haveto be compatible with the glue used immediately thereafter. The facewhich is to form the interior of the bag is treated depending on theproducts that are to be placed in the bag, this surface treatment notbeing very compatible with the creation of the sheath by longitudinalgluing.

In this case, therefore, again there is no application face anddestination face between which the long-acting adhesive is to be locatedonce it has been applied only to the application face (generally hot inliquid form) and then has to be applied cold, months later, by a user.

U.S. Pat. No. 1,546,725, which also relates to the manufacture ofarticles on a machine from materials whose surface has previously beencoated with a product that is incompatible with the glue used. In thiscase, this is essentially paraffin which is removed from the zones bymeans of which the material is glued to form a box. The two flaps fromwhich the paraffin has been removed are fixed to one another immediatelyafter scratching, using the same glue and at the same time, so that onceagain there is no distinction between the application surface and thedestination surface.

U.S. Pat. No. 1,602,597, which is similar to the previous documents andclaim 2 of which is particularly clear with regard to the simultaneousnature of the gluing of the two cleaned parts, on the same machine.

This proves the major importance and specificity of the long-actingadhesive which is used in two steps, the present invention relatingoverall to the problem of the strength of the long-acting adhesive so asto obtain a secure fixing between two separate parts, and thus dealswith this problem both upon application of the adhesive in the factoryand the subsequent application of the same adhesive once it has beenstored and unmasked by removing the protective tape.

The present invention overcomes all the abovementioned drawbacks andmakes it possible to obtain supports: sheets or panels made of anymaterial, provided with a long-acting adhesive for the purpose ofdelayed use of this adhesive, and to do so regardless of the quality ofthe supports, the regularity or irregularity of the surfaces present,the existence or absence of a surface coating, the thinness or thicknessof the materials used.

This is because the aim of the products provided with a long-actingadhesive is to be easily used by non-professional people who haveneither knowledge nor experience nor suitable practical means forefficient use of the adhesive.

It is this single aim which is proposed by the present invention,knowing that achievement of this result complies with industrial meansused in the manufacture in the factory of the products in question,since it has been noted that the quality of the final result depends onthe precision of the manufacturing machine and on the control of anumber of parameters, all this working towards this single aim.

To this end, the subject of the invention is a method for manufacturinga product consisting of a support on which there is a long-actingadhesive and a protective tape for delayed use of said adhesive, forjoining by means of said adhesive two elements of the support, one ofwhich bears a surface known as the “application” surface and the otherof which bears a surface known as the “destination” surface, whichmethod consists in bringing about a relative movement between saidsupport and a station for the coordinated deposition of an adhesive andof a removable protective tape, preferably by moving the support and notthe deposition station, then in applying to the application surface,from the deposition station, a long-acting adhesive either in the formof a prefabricated assembly comprising a base, long-acting adhesive anda removable protective tape, or in the form of two successiveapplications of an adhesive alone and then of a removable protectivetape alone, characterized in that:

-   -   a reference plane is determined near the spot where the adhesive        is deposited, said reference plane being situated either below        the plane in which the lower face of a support is to be located        or above the plane in which the upper face of said support is to        be located,    -   a distance is established which separates the reference plane        and the level at which an adhesive is delivered, said level        being situated near the plane in which the application face of        the support is to be located,    -   long-acting adhesive is delivered,    -   a protective tape which is superposed on the adhesive is        delivered, either simultaneously using a prefabricated transfer        tape or separately,    -   the relative movement is brought about between the support and        the deposition station,    -   a transverse force is exerted on the support so that one of its        faces is constantly pressed against the reference plane,    -   a pressure counter to the transverse force is exerted on the        protective tape and the adhesive, which are superposed.

According to other features of this method:

-   -   the reference plane is arranged on one side of the support and a        pressure is exerted against the face of said support that is        opposite the first;    -   the support being a continuous strip of indefinite length that        is made to move and stretched in a plane, a pressure is exerted        on the strip, transversely to the latter, by means of the        reference plane itself, so that the tension of the strip has the        reactive effect of pressing said strip firmly against said        reference plane;    -   the destination surface, at least, being insufficiently able to        retain the long-acting adhesive during use of the adhesive, that        is to say when the two elements that are to be joined are        brought together, in particular by rapid application and under a        moderate manual pressure, on account of the internal structure        of the support or else on account of an earlier surface        treatment of the support, such as a surface application and/or        coating having an effect that inhibits adhesion of the adhesive,        said destination surface is made to undergo, before it receives        the adhesive previously applied to the application surface by        the two elements that are to be joined being brought together, a        physical, mechanical and/or chemical treatment capable of        improving the adhesion, either by annihilation, neutralization        or attenuation of a rejection effect, or by applying a        corrective product that is able both to fix to the destination        surface and to retain the adhesive, or else by mechanical action        having the effect of reducing the handling requirements during        use of the adhesive;    -   the destination surface being made of paper, it is made to        undergo a treatment either during manufacture of the paper or        after manufacture;    -   the destination surface being made of corrugated cardboard        produced from sheets of paper that have been wound into reels,        treated and assembled, at least one of the sheets of paper is        made to undergo the treatment during production of the        corrugated cardboard;    -   the destination surface being made of corrugated cardboard        produced from sheets of paper that have been wound into reels,        treated and assembled, at least one of the sheets of paper        situated on the outside of the corrugated cardboard is made to        undergo the treatment following production of the corrugated        cardboard;    -   at least part of the surface layer borne by the destination        surface is removed without dissociating the original fibers of        the support, by gentle rubbing and possibly suction of the waste        removed;    -   the corrective product is a product for binding between the        adhesive and the destination surface;    -   the destination surface having a coating product such as kaolin,        a corrective product is applied thereto which is able to pass        through the coating product and fix directly to the support;    -   the corrective product is water-based glue;    -   the destination surface having a soluble coating product, a        solvent is applied thereto which is able to remove at least part        of said coating product;    -   the solvent is an acid such as acetic acid;    -   the support and/or the protective tape is/are subjected to a        heat treatment;    -   the support and/or the protective tape is/are subjected to an        electric treatment;    -   the support and/or the protective tape is/are made to pass        between electrodes which generate a high-frequency electric        field;    -   the protective tape having to receive a print preceded by a        high-frequency treatment, this print is made on the face of the        protective tape that is intended to be applied against the        adhesive, and the application surface, that is to say the        reverse, of the protective tape then has to be transparent so as        to allow the print to appear on the other face, by transparency;    -   the support being made of a relatively rigid material, a        pressure counter to the transverse force is exerted on the        element bearing the application surface so as to obtain a        softening of this element which thus becomes more flexible than        at the start;    -   the pressure counter to the transverse force affects a strip        which is located at the adhesive and the width of which is        slightly greater than that which said adhesive is to have after        it has been applied and spread by pressure;    -   the two elements that are to be joined by the long-acting        adhesive are flaps made of corrugated cardboard, that is to say        comprising grooves sandwiched between two outer sheets, and        which are to be brought together by folding one onto the other        along fold lines, and a pressure transverse to the plane is        exerted on the flap that is to be located on top of the other        one, said pressure being sufficient to crush the grooves and        thus make said top flap more flexible;    -   the pressure counter to the transverse force is calibrated so as        to be greater than the elastic resistance of the material        forming the support;    -   the material forming the support having a honeycomb inner        structure, as is the case in respect of corrugated cardboard,        the grooves of which create longitudinal cells, the pressure is        calibrated so as to be sufficient to break the walls of the        cells forming spacers between two opposite faces of the support        but insufficient to suppress any perpendicular elasticity of        said faces;    -   for the purpose of separately applying malleable adhesive and a        protective tape to a support, firstly the integrity of the        support, secondly the actual presence of adhesive on the support        and thirdly the effective presence of protective tape on top of        the adhesive are checked, and also the arrival of said adhesive,        and if an incident is discovered, that is to say the presence of        adhesive, a break in integrity of the support and/or the absence        of the protective tape, the adhesive is acted upon so as to make        it inoperative, either by neutralizing it or by removing it;    -   as soon as an incident occurs, there is placed on the support,        at the spot where the adhesive is normally located, a material        element which neutralizes the effects of said adhesive,        regardless of whether the adhesive is already present on the        support when the incident occurs or whether it is continuing to        arrive on the support after said incident has occurred;    -   the material element which is placed on the support is a tape;    -   the material element which is placed on the support is a        chemical product;    -   the chemical product is applied by spraying;    -   the chemical product is an anti-adhesive of the silicone type        and is applied in an amount sufficient to cover at least the        entirety of the application zone which bears adhesive;    -   as soon as an incident occurs, the adhesive which has already        been applied is removed and the arrival of new adhesive on the        support is prevented by turning the latter away from its normal        course of application;    -   as soon as an incident occurs, the support is sacrificed by        cutting it near the adhesive that is to be neutralized and by        removing the cut part which bears the adhesive;    -   the adhesive having been deposited near a free edge of the        support, a single cut is made parallel to said edge and the        margin bearing the adhesive, determined by the free edge and the        cut, is removed;    -   the adhesive having been deposited relatively far from a free        edge of the support, two parallel cuts are made on either side        of the part of the support which bears the adhesive and the        strip thus created between the two cuts is removed;    -   the cut part is removed by sucking it from its end and thus        guiding it to a temporary storage area;    -   for the purpose of separately applying malleable adhesive and a        protective tape to a moving support from a deposition station,        comprising:        -   on the one hand a distributor of adhesive (2), said            distributor having one or more distribution orifices,        -   on the other hand a distributor of protective tape, said            distributor having:            -   at least one structure for a reel of protective tape                wound in a spiral and having a free strand,            -   means for unwinding and guiding the free strand,            -   a mechanism for applying said protective tape,            -   characterized in that during the operations of applying                the bead of adhesive, the free strand of the protective                tape is positively driven so that its linear speed just                prior to coming alongside the bead of adhesive already                deposited on the support is equal to the linear speed of                the support with respect to the deposition station, and                in that the bead of malleable adhesive and the                protective tape are calendered together against the                support so as to at least partially laterally spread the                bead of malleable adhesive located between the support                and the protective tape so that the face of said bead of                adhesive that is located against the protective tape                forms into a single plane extending above the highest                point of the application surface on which the bead of                adhesive is applied;    -   in order that the linear speed of the protective tape is equal        to that of the support, the protective tape is driven by a        kinematic mechanism that is synchronized with the moving        support;    -   the protective tape and the support are secured by fixing them        to one another;    -   the protective tape and the support are temporarily secured,        without fixing them to one another;    -   the protective tape is pinched either by its central zone or by        at least one of its side margins;    -   the protective tape and the support are secured by temporarily        pressing them against one another;    -   the pressure is exerted only on the protective tape, that is to        say outside the zone where the bead of adhesive is located        between said protective tape and the support;    -   the pressure is also exerted at the zone where the bead of        adhesive is located;    -   the protective tape and the support are secured directly, and        not only by way of the adhesive located between them;    -   since the support consists of separate panels and the adhesive        is deposited in successive segments of bead over a length of at        most equal to that of each panel, that is to say the deposition        of adhesive is started at each panel by creating a first end of        bead and this deposition is stopped at the space separating two        successive panels by creating on the same panel a second end of        the same bead, the method is characterized in that the support        and the protective tape are secured at least near an edge of the        panels which is located transversely with respect to the        direction of relative displacement and which is closest to the        first end;    -   when the protective tape is applied to the support, the        protective tape is secured to the support very close to the spot        on the support where the protective tape is to be initially        positioned, so that the latter is fixed positively to the        support independently of the state of the long-acting adhesive        located between said support and said protective tape;    -   when the protective tape is applied to the support, the        protective tape is secured to the support by means of        immediate-action glue;    -   the protective tape having one face that is sensitive to the        adhesive and one face that is not sensitive to the adhesive, it        is folded transversely near its free end so as to fold a small        length of the non-sensitive face over on itself along a margin        and so as to bring the margin of the opposite face that is        sensitive to the adhesive onto the face that is to be in contact        with the bead of adhesive previously deposited on the support,        in order that the protective tape is securely fixed to said bead        of adhesive;    -   when the protective tape is applied alone to the adhesive that        has already been applied to the application face, there is        deposited on the latter, continuously or in places, a product        such as a varnish with rapid and strong adhesion power, by        affinity with the long-acting adhesive;    -   for the purpose of separately applying the malleable adhesive        and a protective tape to a support, this protective tape being        stored in a long length by being wound in a spiral on a storage        reel, the inertia of the reel and of the turns of the protective        tape is practically eliminated so as to suppress the resistance        to traction of the protective tape, by differentiating the        operation of extracting the tape from the reel and the operation        of applying said protective tape to the support;    -   prior to any operation of applying the protective tape, a        substantial length of said protective tape is unwound, that is        to say a length which is significantly greater than that of the        segments to be applied to the support, this length of protective        tape is stored between the storage reel and a deposition        station, freely and at random, that is to say not wound up on        itself, said length of protective tape is stored in large folds        free of any attachment and placed against one another without        constraint but more or less aligned in terms of width, in an        intermediate stock, the free strand of the protective tape is        extracted from this intermediate stock in a given length so as        to apply it to a support, whereas a length of protective tape        that is essentially equal to the length which has been extracted        is introduced into the intermediate stock so that said        intermediate stock corresponds to an essentially constant length        of protective tape;    -   the protective tape is positively driven on the one hand        upstream of the intermediate stock and on the other hand        downstream of said intermediate stock;    -   the storage reel is mounted on an idler axle and its rotation is        braked;    -   the braking is stopped when the protective tape is driven        upstream of the intermediate stock;    -   the storage reel is mounted on an axle which is driven in        rotation so as to simultaneously obtain the unwinding of turns        from the reel and the driving of the protective tape towards the        intermediate stock and which is immobilized so as to stop this        unwinding and this driving;    -   for the purpose of separately applying malleable adhesive and a        protective tape to a support, a certain length of protective        tape stored on the reel is extracted, by positive traction of        its free strand, said protective tape is cut at a given distance        from its free end, known as the “downstream” end, so as to        create a segment of desired length, and the latter is applied to        the moving support, on top of the adhesive which has already        been applied;    -   the segment is cut so as to have two free ends, the “downstream”        and “upstream” ends respectively, before being completely        applied to the support;    -   the downstream end is applied to the support before the upstream        end is cut;    -   the upstream end is cut before the downstream end has been        applied to the support;    -   the protective tape is positively driven before the zone in        which it is to be cut;    -   the protective tape is also positively driven after the zone in        which it is to be cut;    -   the protective tape is extracted at a speed which is coordinated        with the linear speed of the moving support so that, at the spot        where the protective tape is applied to the support, the        difference in the speed of the protective tape and the speed of        the support is zero;    -   the protective tape is cut in a given zone and by means of a        rotary cutting member which is actuated at a variable rate        depending on the predetermined length for the segments of        protective tape.

The subject of the invention is also a device for manufacturing aproduct consisting of a support on which there is a long-acting adhesiveand a protective tape for delayed use of said adhesive, for joining bymeans of said adhesive two elements of the support, one of which bears asurface known as the “application” surface and the other of which bearsa surface known as the “destination” surface, this device comprising:

-   -   a machine equipped with means for placing in relative movement a        deposition station and a support, preferably by moving the        support and not the deposition station, along a linear course in        an essentially horizontal plane,    -   a reserve of long-acting adhesive and a reserve of protective        tape either already associated with one another in the form of a        prefabricated assembly comprising a base, long-acting adhesive        and a removable protective tape, known as a “transfer tape”, or        separately, which reserves are located close to the mean plane        in which the support is to be located,

said device being characterized in that it moreover comprises:

-   -   at least one flat rigid part forming a reference plane located        outside the plane in which one of the outer faces of the support        is to be located and parallel thereto,    -   a member having an active part which is located outside the        plane in which one of the outer faces of the support is to be        located and which is arranged such that this active part can        exert on the support a transverse force that affects a width of        said support that is at least equal to that of the rigid part.

According to other features of this device:

-   -   the support having to be made to move in the form of a strip        that is continuous and is stretched longitudinally, the rigid        part and the member having an active part are made as a single        assembly consisting of a plate arranged transversely to the        machine over the entire width of the course of the support, and        of which one face that forms the active part is located beyond        the plane in which one of the two faces of the support is to be        located, so that the continuous strip is subjected over its        entire width to a transverse force due to the tension which        tends to bring it back into a plane located this side of the        active part;    -   the support consisting of separate panels, the rigid part and        the member having an active part are separate and are arranged        on either side of the course of the panels;    -   the rigid part is an immobile stop and the member having an        active part is a lever that is stressed elastically in the        direction of the stop, the active part being formed by a roller        mounted idling at the end of the lever;    -   the lever is connected to a base that is mounted so as to be        able to move between two positions, in one of which, known as        the “active position”, the lever is close enough to the course        of the panels for the roller to be in contact with one of the        faces of said panels, and in the other of which, known as the        “withdrawn position”, the lever is relatively far from its        active position;    -   the base is associated with an automatic control mechanism that        is designed to place the base either in the active position or        in the withdrawn position, depending on whether there is a panel        or an interval between two successive panels opposite the        roller;    -   the stop is located at the end of a head for applying adhesive        at which there terminates a tube for supplying liquid adhesive        from the reserve of adhesive, said head being arranged close to        the plane in which one of the faces of the support is to be        located;    -   the destination surface, at least, being insufficiently able to        retain the long-acting adhesive when the two elements of the        support that are to be joined are brought together, in        particular by rapid application and under a moderate manual        pressure, for example on account of the presence on the support        of a film of synthetic material or of a coating such as a        synthetic material, particularly silicone, a varnish or kaolin,        having an effect that inhibits adhesion of the adhesive, the        machine comprises means for making at least the destination        surface undergo, before it joins the adhesive, a physical and/or        chemical treatment capable of improving the adhesion, either by        annihilation, neutralization or attenuation of an earlier        surface finish, or by applying a corrective product that is able        both to fix to one of the elements of the support and to retain        the adhesive, which means consist either of a mechanism for        removing matter or of a distributor for distributing additional        product, or of an applicator for applying the treatment without        contact, such as a supply of heat by a heating device or an        electric field by a high-frequency generator;    -   the machine is equipped with a member having a rough surface        which is to be in contact with the support so as to remove from        it, by gentle erosion, a fine surface layer without dissociation        of the fibers, at least on the destination surface;    -   the machine is equipped with a suction mechanism having a mouth        located close to the member with a rough surface, for the        purpose of removing waste created by the gentle erosion of the        surface layer;    -   the machine is equipped with a heat treatment assembly which is        to receive at least part of the protective tape immediately        before it is applied to the support;    -   the machine is equipped with an electric treatment assembly        which is to subject at least one of the two elements of the        support that are to be joined to a high-frequency electric field        prior to being joined;    -   the electric treatment assembly comprises two electrodes that        are to generate between them a high-frequency electric field and        between which at least one of the two elements that are to be        brought together and joined must pass;    -   the machine comprises means for printing the protective tape,        said means being located downstream of the electric treatment        assembly in the direction of relative displacement between the        support and the printing means;    -   the device is produced in the form of a machine comprising:        -   an inlet feeder for receiving the support made of cardboard            or similar material, which is in the form of separate panels            that are independent and stacked on the feeder and            previously cut to the desired format and shape in the form            of preforms,        -   a guideway for guiding the preforms one behind the other,            which guideway extends up to a transporter terminating in an            outlet stacker,            -   and is characterized in that the machine moreover                comprises:        -   a distributor for distributing protective tape and            long-acting adhesive, either alone or already associated in            the form of a prefabricated assembly comprising a base,            adhesive and a removable protective tape, the latter being            of great length in the form of reels,        -   a mechanism for cutting said protective tape in a manner            coordinated with the displacement of the preforms for the            purpose of cutting the protective tape close to the two            transverse ends of each preform,        -   a device incorporating means for applying a treatment either            to the support alone or to the protective tape alone or to            both;    -   the device is produced in the form of a machine comprising:        -   an inlet feeder for receiving the support made of cardboard            or similar material, which is in the form of separate panels            that are stacked on the feeder and previously cut to the            desired format and shape in the form of preforms,        -   a guideway for guiding the preforms one behind the other,            which guideway extends up to a transporter terminating in an            outlet stacker,            -   and it is characterized in that the machine moreover                comprises:        -   a distributor for distributing protective tape and            long-acting adhesive, either alone or already associated in            the form of a prefabricated assembly comprising a base,            adhesive and a removable protective tape, the latter being            of great length in the form of reels,        -   a mechanism for applying said protective tape in segments            having a length that is at most equal to that of each            preform,        -   a mechanism for cutting said protective tape which is            coordinated with the application mechanism for the purpose            of cutting the tape into segments that are each located            inside the contour of a preform,        -   a device incorporating means for applying a treatment either            to the support alone or to the protective tape alone or to            both;    -   the device is produced in the form of a machine which is a        corrugator comprising:        -   an assembly for forming the support made of corrugated            cardboard from reels of paper, which support is in the form            of a wide continuous strip that is substantially horizontal            and of indefinite length,        -   kinematic members for constantly or intermittently moving            the continuous strip,        -   a guideway for guiding the continuous strip,        -   an assembly for transverse and/or longitudinal cutting of            the continuous strip so as to create independent sheets,        -   at least one stacker for stacking the independent cut            panels,            -   and it is characterized in that the machine moreover                comprises:        -   at least one head for applying long-acting adhesive alone,        -   at least one distributor for distributing the protective            tape for the long-acting adhesive, said protective tape            being of great length in the form of reels,        -   at least one device incorporating means for applying a            treatment either to the support alone or to the protective            tape alone or to both;    -   the distributor or distributors for distributing protective        tape, either alone or already associated with a prefabricated        assembly comprising a base, adhesive and a removable protective        tape, and the device or devices incorporating the means for        applying a treatment are located above the horizontal continuous        strip, the long-acting adhesive and the protective tape then        being applied to the upper face of said continuous strip;    -   the distributor or distributors for distributing protective tape        and the device or devices incorporating the means for applying a        treatment are located below the horizontal continuous strip, the        long-acting adhesive and the protective tape then being applied        to the lower face of the continuous strip;    -   the long-acting adhesive being applied to the upper face of the        continuous strip, assemblies for distributing malleable adhesive        are located above said upper face;    -   the long-acting adhesive being applied to the lower face of the        continuous strip, assemblies for distributing malleable adhesive        are located below said lower face;    -   the device is designed to separately apply malleable adhesive        and a protective tape and comprises an orifice for distributing        malleable adhesive, members for storing and unwinding the        protective tape, and also a mechanism for applying said        protective tape to the support, at least partly on the adhesive,        which mechanism is arranged downstream of the orifice for        distributing adhesive in the direction of relative displacement,        said device being characterized in that it is equipped with at        least one detector for detecting the presence of protective        tape, the sensitive element of which is located downstream of        the orifice for distributing adhesive and which is connected to        an alarm and also possibly to a mechanism that is designed to        make the adhesive inoperative, either by removing it or by        adding a material element;    -   the device is equipped with a mechanism for removing adhesive        which comprises at least one blade that can move between a        waiting position in which it is located away from the support        and an active position in which it is situated beyond the plane        of the support on which the adhesive has already been applied,        means (possibly automatic) being provided to make the blade move        from one position to the other;    -   the device is equipped with a mechanism for removing adhesive,        comprising at least one cutting element that can move between a        waiting position in which the cutting element or elements are        located away from the support and a position in which they pass        through the thickness of the support;    -   the device being equipped with a mechanism for removing        adhesive, it comprises a removal assembly comprising at least        one pump connected to a tube which opens out close to a storage        area, and a suction apparatus;    -   the device is associated with a distributor for distributing a        material element designed to be applied to the support, at least        partly over all the adhesive present;    -   the distributor comprises on the one hand at least one reel for        storing a sheet such as a tape and on the other hand a mechanism        for delivering the sheet and applying the latter to the support;    -   the device is associated with a reservoir of chemical product        and with an application mechanism particularly for application        by means of spraying;    -   the reservoir is portable and under manual control, in        particular a canister with valve containing a pressurized        propellant gas;    -   the reservoir is fixed and associated on the one hand with at        least one nozzle or with a spraying ramp connected to at least        one tube provided with an electrovalve and on the other hand        with a control mechanism (possibly automatic) for opening and        closing the electrovalve or electrovalves;    -   the device, the deposition station of which comprises:        -   on the one hand a distributor for distributing malleable            adhesive, having one or more distribution orifices,        -   on the other hand a distributor for distributing protective            tape, having:            -   at least one support for a reel of protective tape wound                in a spiral and having a free strand,            -   means for unwinding and guiding the free strand,            -   an applicator mechanism,                -   is characterized in that the deposition station                    comprises:        -   means for positively driving the free strand of the            protective tape and a mechanism for controlling the driving            speed so that, just before it comes alongside the bead of            adhesive already applied to the support, the linear speed of            the free strand of the protective tape is equal to the            linear speed of the relative movement between the support            and the deposition station,        -   a calender formed of two rotating rollers, upper and lower            respectively, which are located on either side of the plane            in which the support equipped with the protective tape is to            extend, and the mutual spacing of which is precise and            advantageously adjustable, the assembly of the support, the            bead of adhesive and the protective tape having to be            engaged in the space located between the upper and lower            rollers so as to calender the bead of malleable adhesive            located between the protective tape and the support, both            having a thickness that is not substantially modified by the            calendering, so that the bead of adhesive is laterally            spread, at least partially, and so that its face located            against the protective tape forms in a single plane            extending above the highest raised point of the application            surface;    -   the machine is equipped with an assembly for applying to the        support a product such as immediate-action glue, a solvent, a        varnish and the like, and which comprises a reservoir for the        product, at least one tube connected on the one hand to the        reservoir and on the other hand to at least one outlet nozzle,        the orifice of which is located close to the course that the        support is to take with respect to the deposition station;    -   the machine comprising a station for depositing adhesive and a        station for depositing protective tape that are offset in the        direction of movement of the support, that is to say the station        for depositing adhesive is upstream and the station for        depositing protective tape is downstream, the orifice of the        product distribution nozzle is located between these two        stations;    -   the machine has a pressure roller mounted so as to rotate and        located in the immediate vicinity of the spot where the        protective tape is to come alongside the support and the bead of        adhesive deposited on the latter, so as to exert a pressure on        the support through the protective tape and the adhesive;    -   the pressure roller is kinematically connected to means for        setting in rotation;    -   the means for setting the pressure roller in rotation are formed        by a mechanism which comprises a drive roller mounted on an axle        and which is to be in contact with the moving support so that,        by tangential friction, the linear movement of the support can        be transmitted to the drive roller, which receives at least one        transmission member connected to the pressure roller;    -   the pressure roller has a central part of smaller diameter than        that of two side parts;    -   the side parts are to be applied directly to the support;    -   the side parts are to be applied to the protective tape located        between said side parts and the support;    -   the side parts have a surface that is not smooth;    -   the half-difference of the diameters of the central part and of        the two side parts is less than the thickness of the protective        tape so as to exert on the latter a driving traction, by        pinching, between the moving support and the rotating central        part;    -   the half-difference of the diameters of the central part and of        the two side parts is less than the total thickness of the        protective tape and of the bead of adhesive previously deposited        on the support, so as to determine by rolling the thickness of        said bead of adhesive;    -   the pressure roller is mounted to rotate on a mobile rig        associated with control means via which the pressure roller can        be placed in one of two extreme positions, one known as the        “remote” position in which the pressure roller is away from the        support and the other known as the “active” position in which it        is in contact with the support, exerting on the latter a        pressure that may possibly be adjustable;    -   the mobile rig is connected to a pneumatic control ram so that        the thrust of the ram on the mobile rig is slightly elastic;    -   the device comprises means for fixing the protective tape to the        support so as to secure them independently of the adhesive        deposited on said support;    -   the fixing means consist of a distributor for distributing        immediate-action glue;    -   the fixing means consist of a mechanism for cutting and        transversely folding the protective tape, designed to fold a        small length of said protective tape from a free end, so that in        the folded part a face of the protective tape that is not very        sensitive to the adhesive is folded back on itself and so that        the opposite face that is more sensitive to the adhesive has a        certain length on the same side of the protective tape as the        face that is not very sensitive to the adhesive;    -   the device being designed to separately apply malleable adhesive        and a protective tape, it comprises a parallelepiped receptacle        defined by six faces, four small faces and two large parallel        faces separated by a distance that is a little larger than the        width of the protective tape, two opposite small faces each        having a passage, one of which is an inlet in which the free        strand of the protective tape coming from a storage reel is to        be engaged and the other of which forms an outlet through which        the free strand of the protective tape is to pass, drive means        being provided to move and guide the protective tape on the one        hand from the storage reel to the inlet of the receptacle and on        the other hand from the outlet of the receptacle to the        deposition station, which means are coordinated so as to conduct        from the reel to the inlet of the receptacle a length of        protective tape that is essentially equal to that which is        conducted from the outlet of the receptacle to the deposition        station, so that there is constantly in the receptacle a        substantial length of protective tape lying at random, that is        to say not wound up on itself, and arranged in wide folds, free        of any attachment and placed one against the other without        constraint but essentially aligned in terms of width by virtue        of the two large faces of the receptacle;    -   the drive means comprise a pair of rollers, at least one of        which is kinematically connected to a motor and which is located        between the storage reel and the inlet of the receptacle;    -   the drive means are associated with a measuring instrument which        makes it possible to determine the length of protective tape        present in the receptacle and which controls the operation of        the pair of rollers so that the length driven towards the inlet        is essentially equal to the length driven from the outlet;    -   the storage reel is mounted to rotate on an axle and is        associated with a braking mechanism;    -   the device comprises a pilot roller against which there bears        the part of the protective tape located between the storage reel        and the inlet of the receptacle when said protective tape is        taut, the pilot roller being in functional connection with the        braking mechanism so that the latter is neutralized when the        protective tape bears against the pilot roller and is made to        have a braking action on the reel as soon as the protective tape        is not taut and no longer bears against said pilot roller;    -   the storage reel is mounted to rotate on an axle and is        kinematically connected to a motor;    -   the pilot roller is in functional connection with the motor so        that the speed of the latter is controlled at an advantageously        adjustable speed when the protective tape bears against the        pilot roller and is stopped as soon as the protective tape is        not taut and no longer bears against said pilot roller;    -   the braking mechanism of the storage reel is constantly in        action and the drive means have a power that is sufficient to        overcome the resistance force due to said braking mechanism;    -   the device being designed to separately apply malleable adhesive        and a protective tape, the reserve of which is a reel on which        it is wound in many turns, this device comprises on the one hand        a mechanism for cutting the protective tape into successive        segments, located between the reel and the deposition station,        and on the other hand a device for measuring the length of the        application surface of the support which is to receive adhesive        and a segment of protective tape, so as to consequently cut said        segment to the desired length before it is entirely placed on        the support so that it is separated from the turns of the reel,        the device moreover comprising drive means for moving and        guiding the protective tape on the one hand prior to cutting        from the reel to the cutting mechanism and on the other hand        after cutting from the cutting mechanism to the deposition        station, the cutting mechanism comprising a cutting member that        can move between a withdrawn position in which it is away from        the course of the protective tape and an active position in        which it is very fleetingly on this course, which member is        secured to a mobile element, the speed of displacement of which,        from the active position of cutting one segment to that of the        following segment, is synchronized with the means for placing in        relative movement the deposition station and the support, the        distance which exists between the cutting mechanism and the        deposition station being smaller than the length of the shortest        permissible segment;    -   the drive means comprise two pairs of rollers, at least one of        each pair being kinematically connected to a motor, one of these        two pairs being located between the reserve of protective tape        and the inlet of the cutting mechanism and the other being        located between the outlet of the cutting mechanism and the        deposition station;    -   the deposition station comprising a pressure roller mounted to        rotate and located in the immediate vicinity of the spot where        the protective tape is to come alongside the support and the        bead of adhesive deposited thereon, the distance which exists        between the pair of rollers located between the outlet of the        cutting mechanism and the pressure roller is smaller than the        length of the shortest permissible segment.

The subject of the invention is also a product, in particular a fibrousproduct, which consists of a part made of cardboard, corrugatedcardboard or a similar material, such as a simple panel, a cut preformwhich is grooved and optionally printed which may have folded and gluedparts, or else a volume article such as a container, characterized inthat this part has at least one slightly adhesive tape arranged on topof a bead of long-acting adhesive applied to at least a first element ofthe part which forms a zone known as the “application zone”, in thepresence of which there is to be located, after folding and/or partialstraightening, a second element of the part along a face known as the“destination surface” without adhesive and thus protective tape, thisdestination surface having greater adhesive retention power than that ofthe rest of the part.

According to other features of this product:

-   -   at least part of the destination surface has traces of an        earlier treatment, such as a surface finish, localized increased        thickness, cavities, irregularities, color or microperforations;    -   at least part of the destination surface is less smooth than the        rest of the part;    -   at least part of the destination surface has a layer of a        product;    -   the elements that are to be brought together are flaps that have        to be folded along lines, at least some of these having        perforations which pass right through the material that forms        the flaps and which are separated by solid parts;    -   the elements that are to be brought together are flaps that have        to be folded and bent over on one another along lines, the        latter being located, for two adjacent flaps, at levels that are        not aligned so that, after folding and bending, the fold line of        the top flap is higher than that of the bottom flap along a        distance that is greater than the thickness of the material        forming the flaps, so that the top flap is slightly inclined        with respect to the bottom flap and not strictly parallel        thereto;    -   the element bearing the destination surface is softer and more        flexible than the rest of the part;    -   the element bearing the application surface has on its face        opposite said application surface a mark to the right of which        the corrugated cardboard is softer on account of the crushing of        its inner grooves to the right of the mark;    -   the long-acting adhesive is covered with a protective tape that        is slightly wider than the adhesive;    -   the long-acting adhesive is covered with a protective tape, the        ends of which coincide exactly with the edges of the part;    -   the long-acting adhesive is covered with a protective tape, at        least one end of which exceeds one of the edges of the part;    -   the long-acting adhesive and the protective tape are placed in a        cavity of the part so that the outer face of the tape is        essentially aligned with the face of the part, without creating        an increased thickness;    -   the protective tape is transparent and bears writing affixed to        its face located against the long-acting adhesive;    -   the protective tape is secured to the cardboard part not only by        the long-acting adhesive itself but also by additional means;    -   the cardboard part bears at least one bead of long-acting        adhesive covered with a protective tape that is secured to the        cardboard part by a mechanical fixing member such as a needle,        staple or the like;    -   the cardboard part bears at least one bead of long-acting        adhesive covered with a protective tape that is secured to the        cardboard part by immediate-action glue deposited in at least        one location.

The invention will be better understood from the detailed descriptiongiven below with reference to the attached drawing. Of course, thedescription and the drawing are given solely by way of non-limitingexample.

FIG. 1 is a schematic view of a device according to the invention,applied to the production of separate panels each having at least oneline of adhesive.

FIG. 2 is a partial schematic view showing a device according to theinvention ensuring the precision of positioning the successive panelswith respect to a deposition station when a panel is located at a headfor delivering liquid adhesive.

FIG. 3 is a schematic view similar to that of FIG. 2 which shows thephase of producing the panels in which an empty space is located at thehead for delivering adhesive.

FIG. 4 is a schematic view of a device according to the invention,applied to the production of a strip of indefinite length having atleast one line of adhesive.

FIG. 5 is a partial schematic view corresponding to that of FIG. 2, thepresence of a strip of indefinite length having the consequence thatthere is no interruption in the presence of support at the head fordelivering adhesive.

FIG. 6 is a partial schematic view showing the closure of a container byfolding two hinged flaps, one of which bears long-acting adhesive.

FIG. 7 is a schematic view of the container of FIG. 1 after it has beenclosed.

FIG. 8 shows the “chewing gum effect” and the start of stretching of theadhesive as a result of the combined action of the two flaps subjectedto a return force returning them to the original flat position.

FIG. 9 shows the sudden opening of the container when the opening forceexceeds the retaining force of the adhesive.

FIG. 10 is a schematic plan view of a flat container blank, cut andgrooved for the purpose of giving volume to a container, in this case abox, designed for dispatching articles contained therein by post orparcel service, to which blank there is to be applied long-actingadhesive and a protective tape.

FIG. 11 is a schematic plan view of a preform made from the blank ofFIG. 10, once the latter has been folded in two and fixed by gluedisposed on an assembly tab.

FIG. 12 is a schematic perspective view of a box to which volume iscurrently being given, from the preform of FIG. 11.

FIG. 13 is a schematic perspective view of the box of FIG. 12, to whichvolume has been given and which is ready to be closed by long-actingadhesive.

FIG. 14 is a schematic perspective view of the box of FIGS. 12 and 13after closure and ready for transport but exposed to the risk ofaccidental opening if it is not treated according to the presentinvention.

FIG. 15 is a blank identical to that of FIG. 10 and treated according tothe invention, before application of long-acting adhesive, and which isthen to form a preform analogous to that of FIG. 11 and then a boxanalogous to that of FIGS. 11 and 12, without any risk of accidentalopening.

FIGS. 16 to 20 are schematic views of a container of known type,allowing packaging of objects of various heights, and which has to bekept in volume and closed by long-acting adhesive.

FIG. 16 shows a flat blank, simply cut and grooved, that is to receivelong-acting adhesive and a protective tape.

FIG. 17 shows a preform made from the blank of FIG. 16 and having afolded and partially glued part for the purpose of forming a containerof variable height, designed for dispatching articles by post or parcelservice.

FIG. 18 is a schematic perspective view of a container obtained bygiving volume to the preform of FIG. 17 and in the progress of beingclosed for packaging a book.

FIG. 19 is a schematic perspective view of the container of FIG. 18,ready to be closed by means of long-acting adhesive.

FIG. 20 is a schematic perspective view of the container of FIGS. 18 and19 but exposed to the risk of accidental opening if it is not treatedaccording to the present invention.

FIG. 21 is a preform analogous to that of FIG. 17 which is to form acontainer analogous to that of FIGS. 18 to 20 but without any risk ofaccidental opening since it has been treated according to the invention,prior to application of long-acting adhesive.

FIG. 22 is a schematic view showing a device implementing the methodaccording to the invention for applying long-acting adhesive and aprotective tape to corrugated cardboard consisting of precut panels, ofgrooved blanks or of preforms which are in the progress of being foldedand assembled by partial gluing, in accordance with one particularembodiment of the invention in which a pressure is exerted, through theprotective tape, on the long-acting adhesive.

FIG. 23 is a schematic view on a larger scale of part of the device ofFIG. 22, specific to this particular embodiment.

FIGS. 24 to 26 are schematic views showing this particular embodimentapplied to adhesive deposited in the form of a single bead that isrelatively thick. Moreover, FIG. 24 is a section on line XLII-XLII ofFIG. 23 and FIG. 25 is a section on line XLIII-XLIII of this same FIG.23.

FIGS. 27 to 29 are schematic views showing the same embodiment of theinvention but using long-acting adhesive applied in a number of smallbeads and to the upper face of the support.

FIGS. 30 to 32 are schematic views showing the same embodiment of theinvention as that of FIGS. 27 and 29 but in which no pressure is exertedthat is sufficient to spread the beads of adhesive.

FIGS. 33 to 35 are schematic views showing a variant of the sameembodiment of the invention using long-acting adhesive applied in anumber of small beads but to the lower face of the support.

FIG. 36 is a schematic view in elevation of a machine according to theinvention, designed to apply long-acting adhesive and a protective tapeto unitary supports consisting of panels made of corrugated cardboardproduced by cutting either a strip of corrugated cardboard of indefinitelength or larger sheets.

FIG. 37 is a partial schematic perspective view showing a variant of theinvention in which a surface layer of the support which is not very ableto retain long-acting adhesive is removed by erosion, on the part of thesupport forming the application surface, prior to application of saidadhesive.

FIG. 38 is a partial schematic perspective view showing a variant of theinvention in which an additional product is spread over the part of thesupport forming the application surface, the surface of which is notvery able to retain long-acting adhesive, prior to application of saidadhesive.

FIG. 39 is a partial schematic perspective view showing a variant of theinvention in which the part of the support forming the applicationsurface, the surface of which is not very able to retain long-actingadhesive, is subjected to an electric field, prior to application ofsaid adhesive.

FIG. 40 is a schematic view in elevation of a machine according to theinvention, designed to apply long-acting adhesive and a protective tapeto a support consisting of a strip of corrugated cardboard of indefinitelength, resulting from the continuous formation of this corrugatedcardboard from reels of paper, this machine being known as a“corrugator”.

FIG. 41 is a partial schematic view of a machine comprising a device forapplying adhesive and a protective tape, in a normal mode of operation.

FIG. 42 is a schematic view analogous to that of FIG. 41, showing theoccurrence of an incident consisting in breakage of the protective tape.

FIG. 43 is a schematic view of one embodiment of the invention appliedwhen the incident shown in FIG. 42 occurs.

FIG. 44 is a view analogous to that of FIG. 43 and corresponding toanother embodiment of the invention.

FIG. 45 is a view analogous to that of FIGS. 43 and 44 and correspondingto another embodiment of the invention.

FIG. 46 is a view analogous to that of FIGS. 43, 44 and 45 andcorresponding to another embodiment of the invention, in two variants.

FIGS. 47 to 54 are schematic views which show an embodiment of theinvention in which the precision of application of the long-actingadhesive and the protective tape is obtained by synchronizing the linearspeeds of the moving support and of the protective tape extracted fromits reserve, by virtue of a pressure roller driven in rotation.

FIGS. 47 and 48 show the situation in which the support is not present.

FIGS. 49 and 50 show the situation in which the support is present atthe pressure roller, prior to deposition of the adhesive.

FIGS. 51 and 52 show a special situation in which the protective tape isalready driven by the pressure roller but the adhesive is delayed withrespect thereto since it is just arriving at the deposition station.

FIGS. 53 and 54 show the situation of current operation in which thesupport is present and receives the malleable adhesive and also theprotective tape.

FIG. 55 is a schematic view showing that the pressure roller may beknurled in its central part.

FIG. 56 is a schematic view showing that the pressure roller may beknurled on either side of its central part.

FIGS. 57 and 58 are schematic views showing two variants of theinvention with regard to the application by the pressure roller of thelong-acting adhesive and the protective tape.

FIG. 59 is a schematic view showing an embodiment of the invention inwhich the pressure roller is driven in rotation by means of atransmission member of the belt type.

FIG. 60 is a schematic view in elevation showing an embodiment of theinvention in which the pressure roller is driven in rotation by amechanism comprising a drive roller which is itself driven by the movingsupport.

FIG. 61 is a schematic view in elevation analogous to FIG. 60, themechanism in this case being in the withdrawn position, the movingsupport not being present at the pressure roller.

FIG. 62 is a schematic perspective view of the mechanism of FIGS. 60 and61.

FIG. 63 is a schematic view showing an embodiment of the invention inwhich an intermediate stock is provided between the protective tapestorage reel and the deposition station.

FIG. 64 is a schematic view showing an embodiment of the invention inwhich a mechanism for measuring and cutting the protective tape isprovided in the vicinity of the deposition station.

Referring to FIGS. 1 to 3, it can be seen how the method according tothe invention is implemented in the case where the supports areindependent panels, whereas in FIGS. 4 and 5 the method is applied to asupport consisting of a continuous strip of indefinite length, which isthe case of strips of corrugated cardboard present on a corrugatingmachine known as a “corrugator”.

Shown in FIGS. 1 to 3 is a heated and insulated reservoir 1 in which acertain amount of adhesive 2 is heated so as to bring it to aconsistency in which it is still pasty but at the limit of the liquidstate, said situation being referred to as “malleable”. By way ofexample, an adhesive of known type is heated to about 175 degreesCelsius, the main thing being to bring the adhesive to the requiredtemperature so that it has a viscosity that is compatible with it beingextruded easily and continuously.

Through a tube 3, the adhesive 2 is brought to an orifice 4 that opensabove the plane in which there is to be situated the upper face of thevarious panels 5 which each form a support that is to receive themalleable adhesive 2 and a protective tape.

The orifice 4 is located at an invariable level N, and either the tube 3is fixed or the orifice 4 is provided on a head 6 which is itselfarranged in a fixed manner, or, if it can be moved for maintenanceand/or adjustment purposes, is secured definitively, possibly by a stop,at the given level N.

The face of the panels 5 which is to receive the adhesive 2, known asthe “application surface”, which in this case is the upper face thereof,is to extend in a plane that is located as precise a distance aspossible from the orifice 4.

This is because the distance D1 which separates the level N from theapplication face is critical in order that the adhesive 2 can be appliedcorrectly, both for fixing it to the application surface in the factoryand for its subsequent real and effective action on the destinationsurface.

According to the invention, there is determined a reference plane Plocated at the distance D1 from that in which the application surface isto be located, and a transverse force is exerted on the panels 5 so thattheir upper face is constantly pressed against the plane P.

In FIG. 1, the plane P is formed by the lower face of a rigid part 7which forms a stop and is distinct from the end of the tube 3 where theorifice 4 is located.

In FIGS. 2 and 3, the orifice 4 is provided on a head 6 for applyingadhesive 2 and is located at the end of a channel 8 that is inclineddownwards from the rear to the front, so as to open out at thedownstream part of the head 6 with respect to the direction ofdisplacement of the panels 5 which is shown by the arrows F1.

The reference plane P is in this case provided on the head 6 itself, theflat and smooth lower face of which forms the stop against which theapplication face is to be constantly held, for all the successive panels5 having the same thickness.

In order to avoid any disruption and a fortiori any obstacle to thedisplacement of the panels 5, the head 6 has a rear transverse step 9 ofrounded shape.

The transverse force is obtained by means of a bearing roller 10 whichforms an active part and which is mounted idling on an axle 11 locatedat the end of a lever 12 connected to a base 13 which is mounted to movein a pivoting manner between two positions.

In FIG. 2, the lever 12 is in the active position, that is to say thebase 13 has been driven (by a mechanism of known type which is notshown) in a pivoting manner in the direction of arrow F2 so that theroller 10 is elastically but securely applied against the lower face ofthe panels 5 (FIG. 2), whereas in FIG. 3 the base 13 has been driven ina pivoting manner in the opposite direction so that the roller is in awithdrawn position, that is to say is away from the spot where the lowerface of the panels 5 is to be located.

With these arrangements, the stop 7 and the active part 10 are locatedon either side of the course of the panels 5.

The alternating pivoting movements of the lever 12 and of the base 13,for bringing the roller 10 into the active position and into thewithdrawn position, are coordinated with the position of the variouspanels 5 so that the roller 10 exerts a transverse force on the lowerface of each panel 5 as soon as the latter arrives at the head 6 and foras long as it is present at this location, and so that this roller 10 ismoved away when there is no panel 5 at the head 6, as is the case duringeach interval which separates said successive panels 5.

This transverse force must not be confused with the simple bearing ofthe panels 5 on banal members of the machine, such as cylinders orbelts, since in this latter case there is no strong elastic forcelocated in a precise manner and calibrated against a reference plane butrather a simple, non-rigid and very imprecise bearing simply on accountof the material forming these belts or the manually controlled positionof the tensioning rollers.

In FIG. 4, it can be seen how the method of the invention is no longerapplied to panels 5 that are separate from one another but rather to asingle support formed by a strip 15 of indefinite length, shown here asbeing a long sheet of corrugated cardboard, on the manufacturing machineor “corrugator” itself, downstream of the elements which are specific tothe manufacture of the double-sided corrugated cardboard and which willbe described below with reference to FIG. 40.

Here, unlike in the previous embodiment of FIGS. 1 to 3, the stop andthe active part are combined to form a single fixed part 16 that isplaced transversely.

The transverse force is obtained by virtue of the positioning of thepart 16 at a level above that which the continuous strip 15 would occupywithout it since, because the latter is very long and flexible, it canbe slightly deflected from its normal course so that its natural nerve,exerted by the corrugator on account of the functions of its variousmechanical stations, presses it constantly against the upper face of thepart 16.

It should be noted that this embodiment is particularly beneficial foruse on a corrugator since the length of the strip, its speed whichfrequently varies and the nature of the means for driving the strip havethe effect of striking the strip perpendicular to its plane, andmaintaining the tension of the part 16 has the fortunate consequence ofattenuating if not suppressing this striking.

In FIG. 4, the upper face of the part 16 is slightly humpbacked so asnot to create excessive stresses on the strip 15, adhesive 2 beingapplied in the vicinity of the part 16 and downstream of the latter withrespect to the direction of displacement of the continuous strip 15,indicated by arrow F1.

In FIG. 5, an application head 6 is located at the part 16 but, sincethe latter is inelastic and fixed, the distance D1 which separates thelevel of the orifice 4 from the plane P must be able to be adjustedprecisely so as to be able to use strips of corrugated cardboard ofdifferent thickness. For a given type of corrugated cardboard, thedistance D1 is adjusted once and for all, and checked and wherenecessary rectified periodically.

The upstream 17 and downstream 18 transverse faces of the part 16 arerounded so as to facilitate the displacement of the continuous strip 15.

The use of long-acting adhesive applies particularly well to containersintended for dispatching articles by post or parcel service but alsorelates to all types of application which require two elements to bejoined by an adhesive, even a long time after the latter has beenapplied to one of these elements.

It is known that only an adhesive makes it possible to join two elementsin an inviolable manner, in particular so as to maintain the volume andclose a container obtained by folding a previously cut and groovedpreform.

“Inviolable” does not mean that it is impossible to separate theassembled elements but rather means that said elements cannot beseparated without leaving visible traces indicating the fraud. This isbecause if opening thereof is fraudulently forced, it is necessary thatthis violation, far from remaining unnoticeable, should on the contrarybe revealed by a visible deterioration of the container, that is to sayby a marked tearing of the fibers when the support is made of fibrousmaterial, which is the case in respect of paper and cardboard(corrugated or otherwise).

Moreover, it is desired that these traces remain apparent even if anattempt is made to reassemble the separated elements, since the adhesiveis to remain inoperative or at least very mediocre and in this wayprevent the original invisible closure from being reestablished as thiswould cover up the fraud.

This is particularly the case in respect of containers supplied flat inthe form of sometimes partially preassembly preforms, and which usersuse one by one to place therein articles that are to be dispatched.Following closure, any accidental opening of the container duringhandling and transport is to be avoided.

Systems with tab closures which are inviolable by nature and involve thepresence of increased thicknesses and relief parts which can be easilycaught and torn, in particular on transporters in sorting centers and intransport containers, have been excluded.

All the closure means which are supposed to be inviolable and are usedwith these tab systems prove illusory since they can be easily foiledwhen the principle of dissimulation on which they are based is known.

The surface irregularities of the supports which are to receivelong-acting adhesive can be compensated by markedly increasing thethickness of the adhesive so as to oblige it by pressure to penetratepartially into the irregularities of the support against which an outerelement is to be fixed.

This is the case of prefabricated plinths made of wood or syntheticmaterial, one face of which is decorative and the other face of which,designed to be fixed to a wall, receives one or more very thick beads oflong-acting adhesive, covered in a fairly imprecise manner withsilicone-coated paper.

It will be understood that this elementary solution leads to high costprices and does not necessarily give good results since fixing remainsrough and imprecise. This is because the thickness of the beads ofadhesive does not make it possible to obtain long reels of transfer tapebecause the diameter of these reels would exceed the limits imposed byindustrial requirements.

It is also possible to keep the same thickness of adhesive but toincrease its width, although this leads to the abovementioned drawback:increased cost price.

In order to overcome this drawback, use is made of double-sided adhesivetransfer tapes, the elastic base of which is supposed to compensate forthe irregularities of the support; however, double-sided tapes are morecomplicated to manufacture than standard transfer tapes and are thusmuch more expensive.

In the field of packaging, and above all in respect of containersdesigned for dispatching articles by post and parcel service, it isessential to ensure a secure closure of each container, which is whyprecautions are taken by using very wide tapes and/or elastic-basetapes. This then results in a high cost price.

The method for separately applying long-acting adhesive and a protectivetape described above does not overcome all the drawbacks encountered inpractice, on account of the very great diversity of the supports thatcan be used.

Some supports have a surface that is very even by nature: sheets ofpaper, parts made of wood and sheets made of rigid synthetic materialswith a smooth surface, compact cardboard, etc.

Moreover, some of these natural supports which are specially treated,particularly with kaolin or varnish, have a surface which makes themfairly unable to retain adhesive.

This is apparently a paradox but the Applicant has observed a surprisingphenomenon which is explained below.

Experience shows that, once the two elements have been fixed to oneanother by the adhesive inserted there between, it is difficult to takethem apart even by exerting a strong but short force, which leads one tothink that the fixing is effective and definitive.

Now, if the elements thus joined are left waiting, they can be unstuckfrom one another as soon as they are subjected to a weak but permanentforce.

This is precisely the case of boxes made of corrugated cardboard fordispatching articles by post or parcel service, closure of which isobtained by long-acting adhesive inserted between two flaps folded overon one another by folding the cardboard.

This is because folding has to be easy and the line along which theflaps have to be folded is marked in advance, during manufacture of thepreform, using a “creasing rule” which is a blade which is not sharp andis integrated into the cutting mold and which, being of smaller heightthan the cutting blades, makes only a simple groove, that is to say amark that does not pass all the way through.

Even if the cardboard is hard, that is to say of good quality, thegrooving should not weaken the board too much since the closed containerwould then risk opening up during handling by cutting along the grooveline which after folding forms a sharp edge of the container.

The result of this is that, with the current knowledge of the personskilled in the art and with the known techniques, it is preferable thatthe cardboard remains virtually intact in terms of its mechanicalstrength and that it retains some tension even if the consequence ofthis is to constantly return the cardboard to its primitive flatposition by stressing the flaps towards their open position.

It is because this spring force of the cardboard is retained that theamount of adhesive is increased, to the detriment of the cost price.

The long-acting adhesive, in turn, always retains a certain elasticityprecisely because it is designed not to solidify. This then produces a“chewing gum effect” which is manifested by a slow unsticking of theadhesive by threads which stretch and weaken the join by unsticking oneby one in an imperceptible but inescapable manner, particularly as afunction of time and the ambient temperature.

This phenomenon can easily be seen with a piece of chewing gum which hasfallen onto the ground and in which one steps involuntarily: it isvirtually impossible for it to become entirely unstuck both from thepavement and from the sole of one's shoe other than by dissolving itchemically; it does however stretch and, while not being able to becomeunstuck, would be incapable of behaving as a resistant adhesive that isto keep two elements one against the other. It should be noted that, oncardboard preforms, these threads detach until the opening forceovercomes the binding force and the flaps unfold suddenly once they haveslightly pivoted with respect to one another while opening, by exertinga traction on the extendable threads of adhesive, knowing that thisadhesive is subject to the sum of the opening forces of the two flapssince one pushes the other in the same direction along a resultantdirected in the direction in which they move apart.

There are three methods for understanding the strength of an adhesive,depending on the manner of exerting an unsticking force:

-   -   in pure traction:        -   two opposing linear traction forces directed perpendicular            to the stuck surfaces are exerted,    -   in shear:        -   two opposing linear traction forces directed parallel to the            stuck surfaces are exerted,    -   by peeling:        -   a single traction force is exerted which is oblique with            respect to the stuck surfaces, that is to say one pulls on            one of the surfaces by lifting it and pulling it at the same            time from one end to the other. This is a type of tearing.

The greatest resistance to unsticking is exerted in shear and in puretraction, whereas under the same conditions the lowest resistance isexerted upon peeling.

In other words, if the greatest resistance becomes weak, the stuck partsbecome dissociated easily.

Now, the chewing gum effect takes place precisely under the conditionsof pure traction and at each point of the stuck surface. In other words,the force is irresistible because it attacks the core itself of theadhesive and the place where its presence is indispensable: unstickingbecomes inevitable.

Thus, this unsticking force is exerted through surfaces broughttogether, transversely to the bead of adhesive and over the entirelength thereof, with an effectiveness that is unfortunately much greaterthan that of a force of manual peeling which is localized and transient.

The peeling force developed by hand is relatively weak because it isexerted counter to the length of the bead over tens of centimeters ofresistance, whereas the natural opening force is exerted counter to thewidth of the bead, over only two or three centimeters, and over theentire length.

The problem which arises is therefore not only that of the quality ofthe adhesive but also that of the capacity of the support to securelyretain the adhesive applied against it, whether this support be theapplication surface or the destination surface.

Here, the word “support” signifies an element which is to be associatedwith the adhesive: application surface, destination surface orprotective tape.

Nevertheless, the parameters of adhesion between the adhesive and theprotective tape are different from those of the adhesion between theadhesive and the elements that are to be joined since in the first casethe protective tape can be removed and fixing can be only temporarysince it is necessary to be able to remove it easily whereas, bycontrast, the fixing of the elements by the adhesive insertedtherebetween has to be definitive and irreversible.

Nevertheless, there is always the same problem of the retention of theadhesive.

There are two habitual phases for obtaining a support for a long-actingadhesive, carried out one after the other in any order:

-   -   secure and definitive fixing of the long-acting adhesive to the        application surface,    -   light and temporary securing of one face of the protective tape        and the adhesive.

According to one variant, the phases are the other way round:

-   -   light and temporary securing of one face of the protective tape        and the adhesive,    -   secure and definitive fixing of the long-acting adhesive to the        application surface.

There are two phases for joining two elements:

-   -   easy removal of the protective tape,    -   secure and definitive fixing of the same long-acting adhesive to        the destination surface, without separation from the application        surface.

The invention recommends a method which makes it possible to obtain anew solution for carrying out these various phases, either by using aprefabricated transfer tape or by manufacturing the tape in situ, asrequired, by applying the long-acting adhesive directly to the supportand covering this adhesive with the protective tape.

This method consists in providing a support with adhesive retentionqualities that it currently does not have, account being taken of thecharacteristics of the raw materials used.

For example, postal services and parcel services use boxes to whichvolume is given one by one, according to dispatch requirements. To dothis, dispatch offices have preforms which are supplied flat so as totake up the minimum amount of storage space and which are sometimespartially assembled by partial folding and gluing of tabs or by joiningtwo adjacent walls edge to edge with a definitively stuck tape.

The tab is folded and glued in the factory, during manufacture of thepreform from blanks made of corrugated cardboard, using high-performanceindustrial means which make it possible, in particular, to use a hot orcold liquid glue which impregnates the receiving cardboard and also thecardboard which is folded and bent onto it before it solidifies.

It is known that corrugated cardboard of the “double-sided” typecomprises three sheets of paper: two flat outer sheets and onecorrugated central sheet so as to form grooves which space apart andmake rigid the two outer sheets which are glued to the grooves.

It was recalled above that some corrugated cardboards have papers ofdifferent quality, in particular a sheet of ordinary quality which is toform the lower face of the products subsequently manufactured, and asheet of better quality for forming the other face which is opposite thefirst, designed to form the visible part of these products. The centralcorrugated sheet is itself also selected as a function of the desiredaim which in this case is the desired mechanical strength.

In order to give it a shiny appearance, the paper manufactured withwhitened pulp may be improved by adding a product, often kaolin, whichgives the white paper a glazed appearance. This method makes it possibleto obtain a paper known as a “coated paper”, that is to say coated witha layer of a product.

Experience shows that long-acting adhesive applied to an element havingsuch a surface adheres very well thereto, and that another elementapplied to the adhesive fixed to the first seems to be impossible tounstick when a peeling action is exerted thereon, namely a hightraction, as has been explained above.

It is found therefore that smooth and flat surfaces or even glazedsurfaces very poorly retain the long-acting adhesive not only when it isapplied to a single surface but when it is inserted between two surfacesto join them and keep them held together for a long time and despite theseparation forces that occur.

The joined elements being brought together by folding the cardboard, thelatter permanently stresses these elements in the direction of theirseparation and constantly returns them to their original position onaccount of the “nerve” of the cardboard, that is to say on account ofits memory which is connected to its folding counter to its elasticnature, as has been explained above.

FIGS. 6 to 9 illustrate the phenomenon of unsticking which the inventionis aiming to overcome.

FIG. 6 shows a box, the body 201 of which is closed by means of twoflaps 202 and 203 which are folded over on one another by pivoting alongfold lines 204 and 205. The upper flap 203 bears a long-acting adhesive2 which was covered with a protective tape, not shown on account of thefact that it has been removed to unmask the adhesive 2.

Once the flap 202 has been folded in the direction of arrow F4, the flap203 is folded over onto the latter in the direction of arrow F5.

The adhesive 2 fixes to the flap 202 and the box is closed, as shown inFIG. 7.

The nerve of the cardboard constantly forces straightening of the flap202 in the direction of arrow F6 and pushes the flap 203 in thedirection of arrow F7, thus adding its action to that which is intrinsicto the nerve of the flap 203.

It follows that if the upper face of the flap 202, which is thedestination surface, is not very sensitive to the sticking of theadhesive 2 and if, moreover, the user does not exert a strong manualpressure on the flap 203 upon closure, the adhesive 2 stretches likechewing gum, as shown in FIG. 8.

The adhesive 2 having been placed in the factory on the flap 203, whichis the application surface, this being carried out hot and usingindustrial means, it adheres much better to the flap 203 than to theflap 202 and, once it has stretched and come unstuck little by littlefrom the flap 202, its resistance becomes less than the straighteningforce of the flaps 202 and 203, so that the box opens all of a sudden,as shown in FIG. 9.

It can therefore be seen that there are only a few traces of adhesive 2on the destination surface of the flap 202 and that the adhesive 2 hasfor the most part, sometimes entirely, remained fixed to the flap 203.

Currently, no treatment is carried out either to the paper or to thecardboard or to the protective tape or even to the adhesive 2 whichremains a product known only to manufacturers specializing in glues andadhesives.

According to the prior art, in order to obtain the desired result with ahigh probability of success, that is to say while undergoing only veryrare accidental incidences of unsticking, it is known only to increasethe amount of adhesive in terms of thickness and/or width, which leadsto high cost prices.

The method of the present invention aims to lower this cost price byincreasing the ease of retention over time of the elements that arebrought together, by virtue of which it is possible to obtain a veryeffective action of the long-acting adhesive 2 which can be used in muchsmaller amounts.

To do this, action is taken on the support, part of which will formeither the application surface or the destination surface or both, whichmeans that action may be taken only on the surface finish of the supportor on its entire structure.

When acting on the surface finish, the operation may be carried outbefore, during or after forming the complete support. When corrugatedcardboard is used, it is possible to carry out a treatment of theoriginal paper that is to form at least one of the two faces of thiscorrugated cardboard, or even to carry out a treatment of the pulp fromwhich the paper is to be made.

The most probable specific situation is that of treating the alreadyformed support, namely the sheets, panels or preforms cut fromcorrugated cardboard.

This is the case in particular of corrugated cardboard, at least oneface of which is coated. It will be recalled that this coating isgenerally obtained by means of kaolin or titanium, or an equivalentmixture, forming a barrier layer which, inserted between the fibers ofthe bare paper and the adhesive 2 that is to be deposited thereon,opposes the penetration of the adhesive 2 into the fibers of the paperand therefore its strong adhesion, regardless of whether this involvesthe application surface or the destination surface.

Referring now to FIGS. 10 to 14, there can be seen an example ofembodiment of an actual box.

From a sheet of corrugated cardboard there is cut the blank of FIG. 10which shows the inner face of the sheet and which is usually made ofpaper of poorer quality than that of the paper of the opposite face(outer face) which, in this FIG. 10, is the hidden face. The hidden faceis moreover often treated so as to have an excellent appearance, inparticular of white color, and bears printed writing and graphics.

The blank of FIG. 10 has two large panels 211 and 212, two transversewalls 213 and 214 and one gluing tab 215.

The large panels 211 and 212 are secured to side walls 216-217 and218-219, and the transverse walls 213 and 214 are secured to connectingtabs 221-222 and 223 224. The inner face of the side walls 216 and 217bears a segment of long-acting adhesive 2 covered with a protective tape20. The part of these walls 216 and 217 which receives the adhesive 2forms the application surface.

Moreover, glue (not visible in the drawing) is applied to the gluing tab215 and/or under the large panel 212 and then the blank is foldedtransversely on itself to produce the preform of FIG. 11 which forms theobject that is supplied and stored flat and is ready to form athree-dimensional box.

To do this, the preform of FIG. 11 is developed into a parallelogram,then the protective tape 20 is removed from the side wall 217, then theconnecting tabs 222 and 224 are folded, then the side wall 219 is foldedover onto the tabs 222 and 224, then the side wall 217 is folded overonto the side wall 219 and this wall 217 is pressed quite hard with thehand so as to secure the two walls 217 and 219 by means of thelong-acting adhesive 2 (FIG. 12).

The box of FIG. 13 is thus obtained, which is still open by its smallface formed by the walls 216 and 218, opposite the small face formed bythe walls 217 and 219 which have been closed by the adhesive 2. It isthen possible to place into the box the articles that are to be packagedand then, in the same way as explained above, the protective tape 20 isremoved from the side wall 216, then the connecting tabs 221 and 223 arefolded, then the side wall 218 is folded over onto the tabs 221 and 223,then the side wall 216 is folded over onto the side wall 218 and thiswall 216 is pressed quite hard so as to secure the two walls 216 and 218by means of the long-acting adhesive 2 (FIG. 13).

The box of FIG. 14 is thus obtained, said box being ready to dispatch.

The outer face of the walls 218 and 219 forms the destination surfacesince it is the one that receives the inner face of the walls 216 and217 with the interposition of the long-acting adhesive 2 (FIGS. 12 and13).

According to the invention, a specific treatment is carried out which,in the example of FIGS. 10 to 14, is localized on the destinationsurface, that is to say the outer face of the walls 218 and 219.

For the sake of clarity of the drawing, the destination surface of thewall 219 is not shown but in FIG. 13 the traces left by a physicaloperation such as scratching, as will be described in more detail below,have been shown by the reference 230.

The effect of this operation is to make the destination surface moreable to retain the adhesive 2 so as to prevent accidental opening of thebox as has been explained with reference to FIGS. 6 to 9, so that theclosed box of FIG. 14 can be dispatched securely without any otherprecaution and can even receive articles that are heavier than thoseusually accepted with this type of container.

After manufacture in the factory of the preform shown in FIG. 11, thelatter is delivered to a place of use where it can remain for arelatively long period of time prior to being used, under randomconditions which may vary from one place to another, in terms of theatmospheric conditions of the place of storage: humidity, temperature,amount of dust, etc.

The adhesive 2 being protected by the tape 20, it does not suffer toomuch from poor storage conditions, while the critical surface is thedestination surface which remains bare and exposed. In order to keep thepreforms in good condition, it is therefore useful to treat thisdestination surface, for example so as to make it anti-static with aview to preventing the deposition and retention of dust, and moregenerally to carry out an anti-dust treatment, for example by means of aproduct sprayed onto this destination surface, and/or to carry out awiping of this surface just prior to removing the protective tape andapplying the adhesive 2 to said destination surface.

It is also possible to mask at least part of the destination surface bymeans of a removable tape which may be identical or similar to theprotective tape 20, that is to say weakly adhesive, and secured by meansof a very small amount of adhesive deposited on the destination surface.

This particular tape may be marked and bear writing relating to the needfor it to be removed in order to close the container produced from thepreform and/or relating to a particular guarantee of good adhesion andthus of an inviolable closure of high quality.

It is necessary to underline the fact that tests have shown that theadhesive retention qualities of a rough destination surface are lessdegraded by dust than a very smooth destination surface, which is whythe properties of a very smooth destination surface are improved byscratching or any other treatment suitable for making it rougher.

It may happen in practice that the application surface, in this case theinner face of the walls 216 and 217, and the long-acting adhesive 2 arecoordinated in a fairly unsatisfactory manner, which may lead to poorclosing of the containers, that is to say to a risk of accidentalopening.

In this case, it is necessary to treat the application surface (innerface) in addition to or instead of the destination surface (outer face).

This is what has been shown in FIG. 15, which shows the blank of FIG. 10prior to application of the long-acting adhesive 2 and after a treatmentsuch as scratching which leaves traces 230 on the inner face of the twowalls 216 and 217.

Of course, the treatment of these walls may not be strictly localized asshown, but rather may concern the entire surface of the walls 216 and217 or even the entire surface of the blank.

FIGS. 16 to 20 show another example of application of the invention, nolonger to a box of fixed volume but to an envelope of variable heightwhich is capable of being adapted to articles of different thickness, inparticular to books of greater or lesser volume and/or to a greater orlesser number of books.

From a sheet of corrugated cardboard there is cut the blank of FIG. 16which shows the inner face of the sheet and which is usually made ofpaper of poorer quality than that of the paper of the opposite face(outer face) which, in this FIG. 16, is the hidden face. The hidden faceis moreover often treated so as to have an excellent appearance, inparticular of white color, and bears printed writing and graphics.

The blank of FIG. 16 comprises two unequal rectangular panels 241 and242, separated by a transverse line formed of a central slit 243 and twofold lines 244 and 245 located at the ends of the slit 243. In order toensure tidy and precise folding, the central slit 243 is interrupted bytwo uncut bridges 246.

The end panel 242 is separated into two flaps 247 and 248 by alongitudinal cutting line 249 that is interrupted by two uncut bridges251 and 252 which secure the two flaps 247 and 248 and by a centralopening 253, the purpose of which is explained below.

The flaps 247 and 248 have two longitudinal fold lines 254 and 255defining two side lips 256 and 257.

Spots of glue 260 are placed along the longitudinal margins of the panel241 over a length corresponding to that of the panel 242, then the panel242 is folded over onto the panel 241, they are pressed together andfixed to one another by virtue of the spots of glue 260 which join thepanel 241 and the lips 256 and 257.

Along the transverse edge of the panel 241 opposite the end panel 242,and over the entire width of the latter, there is applied long-actingadhesive 2 which is covered with a protective tape 20, the margin of thepanel 241 that receives this adhesive 2 forming the application surface.

After folding the blank of FIG. 16, gluing the lips 256 and 257 andapplying adhesive 2 and tape 20, the preform of FIG. 17 is obtainedwhich forms the object that is supplied and stored flat and forms anenvelope that is ready for use.

To do this, the user places a finger into the central opening 253 andpulls sharply on the flaps 247 and 248 so as to break the bridges 251and 252 and straighten said flaps 247 and 248 (FIG. 18).

This uncovers the part of the panel 241 which was covered by the flaps247 and 248 which forms a base 261 for receiving articles that are to bepackaged, such as a single book A shown in FIG. 18.

The flaps 247 and 248 are then folded over onto the book A and they foldprecisely along the edges of the book A so that their free ends pressperfectly against the upper face of this book A.

While keeping these ends against the book A, the assembly consisting ofthe base 261, the book A and the folded flaps 247 and 248 is turned overonto the panel 241 in the direction of arrow F8, the panel 241 foldingtransversely precisely in line with the ends of the side lips 256 and257, then, once the protective tape 20 has been removed, the free end ofthe panel 241 is folded in the direction of arrow F9 of FIG. 19, whichshows both the application surface bearing the adhesive 2 and thedestination surface formed by the outer face of the base 261.

The dimensions of the outer face of the base 261 are precisely knownsince they correspond to those of the end panel 242. On the other hand,the length L1 of the free end of the panel 241 is not known since itdepends on the height H, the latter itself being a function of thethickness of the packaged articles. Consequently, it is not known atwhich point exactly the adhesive 2 will be applied to the outer face ofthe base 261 and the destination surface that has to be treated cannotbe located precisely.

In the examples of FIGS. 10 to 14, on the other hand, the place wherethe destination surface is located is known precisely even before volumeis given to the box and the articles to be packaged are placed therein,since the box has invariable dimensions, although this is not the case,by definition, in respect of an envelope with variable height.

This is why the treatment of the destination surface has to extend overthe entire outer face of the base 261 or, more precisely, betweenextreme limits which correspond on the one hand to the case where, inrespect of a surface sufficient to ensure effective closure of thecontainer, the length L1 of the free end of the panel 241 would be toosmall, and on the other hand to the case where the packaged articlewould be very thin, in which case the height H is virtually zero and thefree end of the panel 241 covers virtually the entire surface of saidouter face of the base 261.

In FIG. 19, reference 230 shows the trace of the treatment of this outerface and it is understood that the tool which has left this trace had auseful length that was a little smaller than that of the base 261.

In practice, it is simpler to treat the entire surface and the benefitoffered by the invention of making it possible to choose the treatmentmeans, in particular depending on the extent of the surface to becovered, can be seen here.

Once the free end of the panel 241 has been folded over onto the outerface of the base 261, pressure is applied strongly by the hand to thisfree end in order to securely press the adhesive 2 onto the destinationsurface, and the filled and closed container of FIG. 20 is obtainedwhich is ready to be dispatched.

A self-adhesive label B bearing the name and address of the addressee isoptionally fixed to the container, either on the top or on the free endof the panel 241 or even on the outer face of the base 261 depending onthe length L1. Self-adhesive labels do not tend to come unstuck and theyadhere perfectly well to corrugated cardboard which may or may not betreated, so that they do not require the presence of treatment traces230, but it will be understood of course that this treatment, even if itis not necessary, cannot be a disadvantage because in all cases itimproves the adhesion capability. As stated above, the treatment mayconsist in a physical operation such as scratching, as will be describedin more detail below.

The effect of this operation is to make the destination surface moreable to retain the adhesive 2 so as to prevent accidental opening of thecontainer as has been explained with reference to FIGS. 6 to 9, so thatthe closed container of FIG. 20 can be dispatched securely without anyother precaution and can even receive articles that are heavier thanthose usually accepted with this type of container.

It may happen in practice that the application surface, in this case themargin of the free end of the panel 241, and the long-acting adhesive 2are coordinated in a fairly unsatisfactory manner, which may lead topoor closing of the containers, that is to say to a risk of accidentalopening.

In this case, it is necessary to treat the application surface (innerface) in addition to or instead of the destination surface (outer face).

This is what has been shown in FIG. 21, which shows the preform of FIG.17 prior to application of the long-acting adhesive 2 and after atreatment such as scratching which leaves traces 230 on the inner faceof the panel 241.

Of course, the treatment of this margin may not be localized as shown inFIG. 21, but rather may concern a large part or even all of the innerface of the blank.

FIGS. 22 to 35 illustrate the way in which this method is carried out:

On a machine 300 having a conveyor 301, panels of corrugated cardboard 5are made to circulate in the direction of arrow F1 so that theysuccessively pass a number of assemblies which are, in the order inwhich they are passed:

-   -   an assembly 400 designed to mechanically treat one or more parts        of the panels that are intended to form application surfaces,        and to suck up and remove the waste produced by this treatment;    -   an assembly 500 for applying the long-acting adhesive 2;    -   an assembly 600 comprising one or more reels of protective tape        20 and the means for placing it on top of the long-acting        adhesive 2;    -   an assembly 700 provided to crush, at least slightly, through        the protective tape 20, the previously applied adhesive 2.

The assembly 400 comprises a mechanical member for scratching at leastpart of the upper face of the panels 5. This mechanical member is inthis case a brush 401 that is driven in rotation by means of a motor 402by a transmission 403 of any type suitable for this function.

It would be possible to conceive that the direction of rotation of thebrush 401 must be the anticlockwise direction, arrow F10, when thedirection of displacement of the panels 5 is that of arrow F1. In fact,this direction of rotation depends on a number of parameters: surfacefinish and drive speed of the panels 5, power of the drive means, etc.

Depending on the circumstances, one may then be led to choose theanticlockwise direction, in which case it is necessary to adopt arotation speed such that the tangential speed in the zone of contactwith the panels 5 is different from the travel speed of the latter, as aresult of which the desired erosion effect would not be obtained.

In any case, the brush 401 causes fine particles to be removed at thesurface, which particles should preferably be trapped and removed,although this is not indispensable, and in this case this is obtained bymeans of a suction device 404 connected to a mouth 405 by one or moretubes 406 and a collector 407.

During operation, the fine particles are sucked up through the mouth 405and, via the tube(s) 406 and the collector 407, arrive at the suctiondevice 404, from where they are removed by any means known to the personskilled in the art.

Downstream of the assembly 400, in the direction of travel of the arrowF1, the panels 5 therefore have part of their surface suitably treatedfor receiving the adhesive 2.

The latter is stored in a reservoir or “melting machine” 1 which isequipped with heating means (not shown) suitable for melting theadhesive 2 to a temperature at which it is malleable, that is to say ina fluid state close to the liquid state, and which is equipped with oneor more tubes 3 which end at one or more orifices 4 that open outimmediately above the panels 5. As explained above, the tube 3 may beinsulated by a sleeve 501 which makes it possible to maintain thetemperature of the adhesive 2 up to the immediate vicinity of theapplication surface on the panels 5.

The orifices 4 may be of different types depending on whether a singlebead of adhesive 2 or a number of beads is/are to be deposited onto thepanels 5, depending on whether the adhesive 2 is to be deposited inparticular by gravity alone or spread. Each orifice 4 may therefore beformed by a simple nozzle (FIGS. 22 and 23) or by a “lipped nozzle” (notshown).

The adhesive 2 arrives hot on the application surface of the panels 5and cools rapidly so as to end up in a pasty state in which it is stillmalleable and by virtue of which it adheres sufficiently to the panels 5so that the latter entrain it in their displacement in the direction ofarrow F1, in the form of one or more beads.

The panels 5 and the adhesive 2 that they bear arrive at the assembly600, which comprises one or more reels 22 bearing a great length ofprotective tape 20 which passes an application mechanism 601 thattensions, guides and distributes the protective tape 20 just above thebead of adhesive 2, to which it adheres slightly.

The panels 5, the adhesive 2 and the protective tape 20 that they beararrive at the assembly 700, which comprises the roller 21, the axle ofwhich is borne by a mounting 701 connected to the piston of a hydraulicram 702.

The piston of the ram 702 is mounted to move vertically in the directionof arrow F1 so as to make it possible to adjust as precisely as possibleto position in space of the lower generatrix of the roller 21, since itis advantageous if the bead of adhesive 2 is not crushed inconsideratelybut calendered to a precise calibrated thickness so that its upper faceand the protective tape 20 layered thereon are in a plane parallel tothe plane P and at a height h of the latter that is sufficient to fillthe cavities that appear on the surface on account of the grooves of thecorrugated cardboard and, at the same time, to cover the reliefs thatalternate with the cavities (see FIGS. 15 and 16).

Of course, if the surface finish of the panels 5 is excellent, theadhesive 2 may be applied less carefully but nevertheless at the risk ofa mediocre application of the adhesive 2 which tends to deposit more onthe reliefs than in the cavities, which greatly reduces the surfacecovered with adhesive and thus degrades the adhesion capability.

FIGS. 24 to 35 schematically show, in four variants of the method, theoperations of the machine 300, considered respectively after theassembly 500, at the assembly 600 and after the assembly 700.

FIGS. 24 to 26 correspond to the variant in which an orifice 4 deliversthe adhesive 2 from top to bottom in a vertical flow 801 which isdeposited on the panel 5 and extends horizontally in a single bead 802.It can be seen in FIG. 24 that the bead 802, considered immediatelyafter its arrival on the panel 5, still has very substantially the samecross section as that of the flow 801, that is to say in this case acircular cross section.

After a few seconds of displacement in the direction of arrow F1 beyondthe orifice 4, the bead of adhesive 802 has slightly subsided and itscross section is flattened with a lower flattened portion applied to thepanel 5 and an upper flattened portion 803 on which the protective tape20 is placed along a contact surface that is much greater than therewould have been with the sole upper generatrix of a bead 802 with acircular section.

The protective tape 20 thus adheres to the bead 802 sufficientlystrongly for it to be entrained in the displacement of the panel 5 andtowed in unwinding from the reel 22, especially if it is also drawn bythe roller 21.

As mentioned above, the roller 21 is located at a specific height thatis less than the total thickness of the bead of adhesive 802 which hasalready been flattened and the protective tape 20, so that the assemblyis pressed and the bead 802 becomes a flat layer 804 having a thicknessthat is precisely calibrated and having the same width as the tape 20(FIG. 26).

Referring now to FIGS. 27 to 29, another variant can be seen in whichthe adhesive 2 is distributed in several (in this case four) flows 805which thus form distinct beads 806.

This variant allows better adhesion of the adhesive 2 to the panels 5and of the protective tape 20 to the adhesive 2, since the protectivetape 20 is placed over all the distinct beads of adhesive 806, that isto say in this case four strips, whereas with the variant of FIGS. 24 to26 the same protective tape 20 was placed over just a single strip. Thefinal result is the same if a pressure is applied to the adhesive2-protective tape 20 assembly by means of the roller 21, and FIG. 29 isidentical to FIG. 26.

However, it is also possible to exert only a low pressure, designedeither to increase the area of the flattened portion 803 of the singlebead 802 or to slightly flatten the four beads 806.

In this case, there is no formation of a flat layer 804 but rathersimply of a slight flattening of the beads 806 which remain separateunder the protective tape 20 at the exit from the machine 300 (FIGS. 30to 32).

A pressure, however slight, is useful so that the protective tape 20adheres to the adhesive 2, but it may prove to be superfluous if thenature of the adhesive 2 and the material of the protective tape 20 arewell coordinated to fix to one another with a force that is great enoughfor the adhesive 2 to entrain the protective tape 20 along the machine300 and small enough for it to be possible to subsequently separate themfrom one another when it is desired to remove the protective tape 20 soas to unmask the adhesive 2.

Referring now to FIGS. 33 to 35, a variant of the method of theinvention can be seen in which the adhesive 2 is not deposited bygravity, from top to bottom, onto the upper face of the panels 5, butrather by projection from bottom to top onto the lower face of thepanels 5, in this case forming five distinct beads 807.

In order not to overload the drawing, the orifices of the applicationdevice have not been shown since the embodiment of this device is per seknown to the person skilled in the art, knowing that these orifices arelocated at the end of application heads, the outlet orifice of which isto be oriented from bottom to top. As regards the adhesive 2, this musthave a viscosity suitable for this mode of application by projection andbe made to move at a pressure and at a speed that are correctlycoordinated for immediate fixing to the lower face of the panels 5.

This variant is possible on account of the low specific mass of eachbead 807 and is to be adopted when the manufacturing conditions thusrequire.

This is the case, in particular, when the adhesive 2 is applied on acorrugator, as shown in the diagram of FIG. 40.

This is because it may happen that the distribution of the variouslayers of paper (upper paper, corrugated paper of the grooves, lowerpaper) and also the cutting of the blanks for certain objects have theconsequence that the application surface, which at the end ofmanufacture will be located on the lower face of the blank of FIGS. 10and 16 for example, is the lower sheet of paper of the corrugatedcardboard being manufactured on the corrugator of FIG. 40.

At present, these circumstances make it very difficult to applylong-acting adhesive, unlike the method of the invention which has justbeen described.

The machine 300 of FIG. 22 may be of various types, either a specificmachine whose sole purpose is to apply adhesive 2 and a protective tape20 to panels of corrugated cardboard that have been cut into rectanglesfor the purpose of subsequently cutting out blanks, or to blanks orpreforms that have already been cut, or a machine having otherfunctions: machine for folding and collecting cut blanks, cutting press,printing machine, machine for applying assembling tape which is known inthe United States under the generic name of “taper”, etc.

It will thus be understood that the assemblies 400, 500, 600 andoptionally 700 may be considered as subassemblies which are groupedtogether to form a whole, which itself forms a large assembly that iscomplementary to an existing machine or a machine that is speciallydesigned for this purpose.

The method according to the invention therefore has various specificapplications, each corresponding to precise functions of a chain forsequentially manufacturing products in steps, or on the contrarycorresponding to a complex unit that incorporates the device of theinvention described with respect to FIG. 22 along with other functions.The only operation common to all the machines is the displacement of thesupport (the panels 5 of FIG. 22) that is to receive the adhesive 2 andthe protective tape 20, hence the need for a conveyor of the type 301 ofthe machine 300, and also materialization of the reference plane P.

FIG. 36 schematically shows a specific machine 900 whose sole purpose isto apply adhesive 2 and a protective tape 20 to panels 5 that have beencut into rectangles and are intended to then be cut into blanks having ashape and dimensions corresponding to the objects that are to beobtained. Two examples of such blanks are shown in FIGS. 10 and 16.

Moreover, some blanks have to be formed and “mounted” so as to be shapedinto preforms having folded and glued parts, which is the case inrespect of the preforms of FIGS. 11 and 17.

The machine 900 comprises a frame 901 that is associated with twoconveyors 301, each having an endless belt passing over drive pulleys902, guide pulleys 903 and tensioning pulleys 904, so as to obtain anupper strand 905 which extends in a same plane located opposite thelower strand of the endless belts 906, the upper strand 905 and thelower strand of the belts 906 being arranged to as to together entrain,by strong friction, the panels 5 inserted between them.

The conveyors 301 are made to move in the direction of arrow F1 inrespect of the upper strand 905, by a motor 907 and a transmission 908with the interposition of a clutch 909. For the sake of clarity of thedrawing, the mechanical elements which provide the connection betweenthe transmission 908 and the drive pulleys 902 have not been shown.

Upstream of the frame 901, considering the direction of arrow F1, thereis a device 910 for receiving a stock of stacked panels 5 anddistributing these panels 5 one by one, this device being known as a“feeder”.

The feeder 910 comprises an inclined support 911, an endless beltconveyor 912 and a distribution regulator 913.

The feeder 910 and the operation thereof will not be described in anygreater detail as they are well known to the person skilled in the art.

Downstream of the frame 901, considering the direction of the arrow F1,there is a device 920 for receiving and superposing the panels 5 on topof one another once they have each received the long-acting adhesive 2and the protective tape 20. This device is known as a “stacker” since itreceives the panels 5 one by one and stacks them on top of one another.

An endless belt conveyor 921 has a lower end 922 located in theimmediate vicinity of the downstream end of the upper strand 905 andbelow the level of the latter so that the panels 5 automatically passfrom the strand 905 to the upper strand 923 of the conveyor 921 whichentrains them in the direction of arrow F12.

The conveyor 921 is inclined and its upper end 924 is located in theimmediate vicinity of a support 925 mounted to move with respect tofixed columns 926. As the stack of panels 5 increases in height at agiven rate and until it corresponds to a total number of panels 5, thesupport 925 lowers so that the level at which the panels 5 are depositedby the conveyor 921 remains more or less constant.

When the support has reached the bottom position, the number of panels 5has reached the maximum possible number and the entire stack isevacuated, the support 925 is brought back to the top position and thecycle is repeated.

The stacker 920 and the mode of operation thereof will not be describedin any more detail since they are well known to the person skilled inthe art.

In FIG. 37, the mechanical member of the assembly 400 is a brush whichis driven in rotation in the anticlockwise direction and which, byscratching, removes at the surface particles extracted from a more orless thick layer of the upper face of each panel 5, and which leaves atrace 230 which can be seen more or less easily with the naked eye orusing a magnifying optical instrument.

A mechanical treatment of the application surface is thus obtainedupstream of the assembly 500 for applying adhesive 2.

FIG. 38 schematically shows another example of an assembly 400 having anactive member which does not remove material from the panels 5 butrather deposits on their upper face a corrective product which leaves atrace 230 that can be seen more or less easily depending on itscomposition.

For example, the product may have a chemical composition which allows itto act on the material of the panels 5, in particular by reacting withthe kaolin which covers the upper face, so as to create an applicationsurface that is able to strongly attach to the adhesive 2 deposited bythe assembly 500.

Such a product may be a water-based glue for example.

The product is stored in a reservoir (not shown) from where there comesa tube 408 equipped with a lipped nozzle 409 which distributes theproduct horizontally and in a fine layer.

FIG. 39 schematically shows an assembly 400 which makes it possible toapply an electric treatment to the panels 5.

This assembly 400 comprises a high-frequency current generator 410comprising two connections 411 and 412 for two electrodes 413 and 414positioned on either side of the course of the panels 5.

When the generator 410 is operating, it causes the formation of a strongelectric field which is passed through by the panels 5 circulating thein direction of arrow F1.

This electric field causes microsparks, which is why this method isknown as “spark erosion”, said sparks creating miniscule burns on thepaper forming the upper and lower faces of the panels 5, thus allowingthe formation of microperforations which are invisible to the naked eyeand the size of which has been exaggerated in FIG. 39 in order to makeit easier to understand this mode of operation applied to supports thatare to receive a long-acting adhesive 2.

By virtue of these microperforations on the application surface, theadhesive 2, which is hot and virtually liquid, penetrates slightly intothe thickness of the panels 5 and in any case enough to attach stronglythereto.

It should be noted that, the electrodes 413 and 414 being symmetrical,the microperforations are located on both the faces of the panels 5,which may be of great advantage for preparing the application surface onany one of these faces when such an assembly 400 is located upstream ofa machine which applies the adhesive 2, since it is not necessary tomark the face that is to have the application surface.

It will be recalled that, although the operations of the assemblies 500and 600 are necessarily grouped together and synchronized, the same isnot true in respect of the operations of the assembly 400 which may takeplace in isolation and a great way upstream of the application of theadhesive in the overall manufacturing process.

Thus, referring now to FIG. 40, there can be seen the functional diagramof a corrugator, that is to say of a machine which produces a continuousstrip of corrugated cardboard from sheets of paper on reels.

It is known that it is possible to manufacture various types ofcorrugated cardboard using one and the same machine: a strip ofcorrugated paper alone, a corrugated sheet and a single sheet of paper(“single-sided”), a corrugated strip between two sheets of paper(“double-sided”), an alternating arrangement of papers and corrugatedsheets (“double-double”), etc.

In order to illustrate the invention applied to a corrugator, theexample of manufacturing “double-sided” has been selected, this beingthe most conventional corrugated cardboard product, although it will berecalled that the invention applies to any type of support, not onlythose made of all the possible types of corrugated cardboard but alsothose made of compact cardboard and similar materials.

The corrugator 1000 of FIG. 40 comprises a frame (not shown) associatedwith an endless belt conveyor 301 which transfers, in the direction ofarrow F1, a sheet of indefinite length coming from the assembly bybonding three sheets of paper 1001, 1002 and 1003 stored in reels ofgreat length 1004, 1005 and 1006.

The sheet of paper 1001 passes between two groove-forming rollers 1007and 1008 which create transverse grooves to produce a corrugated strip1009.

The sheets of paper 1002 and 1003 pass over guide rollers 1010 and 1011so that they come alongside the grooved sheet 1009 on either side andare fixed to said grooved sheet by gluing so as to form a strip ofcorrugated cardboard 1012 of indefinite length and, so to speak, endlesssince, as soon as a reel 1004 and/or 1005 and/or 1006 is empty, it isreplaced by another reel and the end of one sheet and the start of thenext sheet are glued to one another so as to allow continuousproduction, without stopping the machine.

Since corrugators are well known per se, the person skilled in the artknows that the sheets of paper, prior to being glued, have to beconditioned or preconditioned, in particular humidified andvapor-heated, and that the corrugator must have tensioning, guiding,drying, cooling, and speed-regulating means that are coordinated to forma whole.

All the functions of the corrugator are controlled by computer usingpreset programs that are commonly used. There is thus no need todescribe in detail all the elements which make up a complete and workingcorrugator.

As soon as the strip of corrugated cardboard 1012 is formed, it isengaged on the conveyor 301 and, after a course of greater or lesserlength depending on the technical requirements to which reference wasmade above, the strip 1012 arrives at the assembly 400, which is shownin FIG. 40 as being of the type shown in FIGS. 1 and 22.

Following appropriate treatment, the strip of corrugated cardboard 1012ends up at the assembly 500 which applies one or more beads of adhesive2, as explained with reference to FIGS. 24 to 35, then at the assembly600 which places a protective tape 20 on the adhesive 2 that has alreadybeen applied.

The corrugator produces a strip 1012 that is very wide, around 2.5meters, and the products which are best suited to the presence oflong-acting adhesive 2 are cut from sheets which are much less wide.This is why the assembly 400 is made up of a number of members 401, anumber of mouths 405 and a number of tubes 406 formed as subassemblies,the position of which can be adjusted via the corrugator 1000 so as toposition as many subassemblies as necessary a given distance from theedges of the strip 1012, in order to apply to this strip 1012 thedesired number of lines of adhesive 2: beads 802 or 806 and tape 20 toapplication surfaces created beforehand.

It will be understood that adhesive 2 and its protective tape 20 can bedeposited continuously by a corrugator if the products produced from thestrip 1012 are to be provided with adhesive over their entire width ortheir entire length, from edge to edge, in which case the bead ofadhesive 2 and the protective tape 20 are continuous.

The strip 1012 then arrives at the outlet of the machine where there isa cutting assembly of a type known per se.

This assembly cuts the strip 1012 both transversely, as shown by a blade1013 mounted to move perpendicular to the plane of the strip 1012 in thedirection of arrow F13, and longitudinally by means of cutting disksmounted to rotate with respect to supports, the position of which can betransversely adjusted as a function of the widths which are imposed bythe production program, which takes account of the desired formats forthe products to be manufactured from the sheets obtained at the outletof the corrugator 1000. These means, their mode of operation and thecontrol thereof do not form part of the present invention and are knownto the person skilled in the art.

By depositing the adhesive 2 and its protective tape 20 on a corrugator,many advantages are obtained:

-   -   sequential or continuous application of the prior treatment        (assembly 400), of the application of adhesive 2 (assembly 500)        and of the application of tape 20 (assembly 600),    -   supply of the transformation machines with products that have        already been prepared,    -   work sometimes obscured, taking up at the corrugator outlet        being inevitable, even with products that are not provided with        adhesive 2,    -   no need to take up products and transfer them from machine to        machine,    -   high speed of production,    -   economy of production costs,    -   etc.

Once the strip 1012 has been cut by the cutting assembly 1013, panels 5are collected which are evacuated to a stacker 1020 by an outletconveyor 1021, the whole functioning as described with reference to FIG.36 since the product which leaves the corrugator 1000 is of the samenature as that which leaves the machine 900: panels 5.

It can be seen from the above description that the elements placedagainst one another are held together very effectively by means of thelong-acting adhesive.

This result is obtained despite the counterforces due to the nerve ofthe cardboard when the object is formed from blanks and from preformsmade from sheets.

An additional means recommended by the invention is to reduce the forcewhich counters the effects of the long-acting adhesive 2, and to do soin two ways which can be combined:

-   -   It is known that when the two elements that are to be joined by        the long-acting adhesive 2 are flaps that are to be positioned        by folding and placing them on top of one another along lines,        the latter are formed at levels that are not aligned so that,        after folding and placement, the folding line of the top flap is        higher than that of the bottom flap.

This distance must in theory be exactly equal to the thickness of thebottom flap. According to the invention, this distance is established asbeing greater than normal, so that the top flap may be slightly inclinedtowards the bottom flap and not strictly parallel and even less inclinedin the other direction.

-   -   Likewise, when the two elements that are to be joined by the        long-acting adhesive 2 are flaps that are to be positioned by        folding along lines, it was recalled above that this folding        must be easy and that the line along which the flaps are to be        folded is marked in advance, during manufacture of the preform,        by means of a creasing rule which is a blade that is not sharp        and is integrated into the cutting mold and which, being of        smaller height than the cutting blades, makes only a simple        groove, that is to say a mark that does not pass all the way        through.

According to the invention, these lines are formed by perforations whichpass through the material forming the flaps and which are separated bysolid parts.

The groove-forming tools are therefore formed by an alternatingarrangement of creasing rules and cutting blades and there are more orless cutting blades depending on the nerve of the cardboard that it isdesired to cut and, in any case, weaken.

The cutting blades may be simple stamps, in which case there must bemore of them than there are blades whose cutting thread may extend notonly over a single point but rather over a small length.

As the long-acting adhesive 2 is designed to be used a greater or lesserlength of time after it has been applied to the application surface, itis active as soon as it is applied and remains so for a long time, sothat it has to be covered with protective tape 20 which can easily beremoved at the time of use of the adhesive 2 and which neutralizes thelatter so as to avoid any accidental bonding, in particular when thesupport to which the adhesive 2 is applied is handled or subjected tomechanical treatments in machines, as is the case in respect of panelsmade of cardboard, particularly corrugated cardboard, for producingcontainers: printing, cutting, folding, assembly, etc.

It will be understood that a cardboard panel introduced into a machinewhile the adhesive 2 that it bears is active and not isolated by theprotective tape 20 will cause expensive disturbances in respect of thetime it takes to make the machine work again and in respect ofproduction losses.

The parts of the machine are smeared with the adhesive 2, the cardboardpanel is violently thrown off its normal course, fragments attached tothe panel are introduced into difficultly accessible spots and,moreover, it is necessary to immediately stop the machine, clean it andset it working again after a repair time of greater or lesser lengthdepending on the characteristics of the machine, without taking accountof the losses of material due to this sudden stop.

The use of containers made of cardboard provided with long-actingadhesive is rapidly expanding on account of the many advantages offeredby such an adhesive: in particular easy closure and inviolability.

It is thus inevitable that long-acting adhesive is applied on machinesthat are very different from one another and are increasingly complexsince such an adhesive 2 is already applied on corrugators (FIG. 40)which have a very large production capacity, operate at high speed andare extremely complex since the process starts with reels of paper whichare very delicate to handle and then the various sheets of paper have tobe heated and humidified, glue has to be applied in order to assembleone or more corrugated sheets to at least one flat sheet, the wholerequiring an installation of several tens of meters in length, equippedwith powerful motors and associated with delicate mechanisms.

There is therefore no question of taking the slightest risk of anincident due to the application of adhesive on a corrugator. However,such a risk is no less serious in respect of less important machinessuch as folding-collecting machines for example.

The precautions that are currently taken consist essentially inparticularly vigilant monitoring of the protective tape distributors inorder to avoid any interruption in the laying thereof.

By prudence, a method is also adopted which consists in applying theadhesive 2 and its protective tape 20 on a specific machine thatproduces panels 5 bearing this adhesive 2 and its protective tape 20which are then treated on a folding-collecting machine.

The latter, which itself carries out a complex industrial process, iskept away from any incident during application of the adhesive 2 sinceit only receives cardboard panels 5 or preforms, the adhesive 2 of whichhas already been correctly provided with its protective tape 20.

If such an incident occurs, the consequences are slight since repair ofthe machine is limited to manually removing one or more panels 5, andrecommencing the application of adhesive 2 and the laying of protectivetape 20. While the machine is stopped, the panels 5 that are to betreated remain in place at the start of the machine, stationary sincethey are not undergoing any treatment, unlike in the case of applyingtreatment at the inlet of a corrugator for example.

In any case, regardless of the machine in question, it is necessary toanticipate incidents and to remedy them quickly and effectively if suchan incident should occur despite the precautions taken.

The present invention makes it possible to apply adhesive 2 to anysupport, on a pre-existing machine or on a specially designed machine,regardless of the complexity of the industrial process used andregardless of the severity of an incident relating to the application ofa long-acting adhesive 2 and its protective tape 20.

Referring to FIG. 41, there can be seen a machine part treating asupport which is in this case made of corrugated cardboard, and whichmay thus be a corrugator, a folding-collecting machine or a specificmachine.

It can be seen that a sheet of corrugated cardboard, which has alreadybeen produced and may be continuous or cut into panels, moves in thedirection of arrow F1 and firstly passes below a device 500 for applyingadhesive 2, said device comprising a reservoir 1, a tube 3 and adistribution orifice 4, and then passes below a device 600 for applyinga protective tape 20, said device comprising a storage reel 22 turningin the direction of arrow F14 when the protective tape 20 is unwoundnormally, a deposition mechanism 601 and a pressure roller 21 by meansof which the tape 20 is applied firmly against the adhesive 2, extendingor not over the part of the support that is not provided with adhesive,at the sides and/or at the ends of the bead of adhesive 2. In this way,there is applied to the corrugated cardboard support a bead oflong-acting adhesive 2 and a protective tape 20 which completelyisolates the adhesive 2 and prevents it from adhering to anything.

The support thus produced continues on its course through the machine,during which it comes into contact with various mechanical members:cylinders, guides, sensors, cutting devices, stackers, pressers, etc.

All these machine parts remain intact on account of the fact that theadhesive 2 is completely isolated by means of the tape 20, the thicknessof the assembly being small and taken into account during machinesettings where necessary.

In order to monitor that these operations are being carried outcorrectly, a detection circuit is set up which is symbolized byreference 1040 and in this case comprises:

-   -   a pair of photoelectric cells 1041-1042 and a conductor 1043 for        monitoring the integrity of the support and/or its transverse        cuts;    -   a pair of photoelectric cells 1044-1045 and a conductor 1046 for        monitoring the correct arrival of adhesive 2 on the support;    -   a pair of photoelectric cells 1047-1048 and a conductor 1049 for        monitoring the effective presence of protective tape 20.

The conductors 1043, 1046 and 1049 terminate at a controller 1050 whichmay be more or less complex, comprising a computer and managementsoftware, connected to an alarm 1051 and comprising a connection 1052when the controller 1050 is to not only trigger the alarm 1051 but alsoto automatically control the entry into operation of a safety devicewhen an incident occurs.

In FIG. 42, it can be seen that the support is intact and that ittherefore continues its course in the direction of arrow F1, that theadhesive 2 is still arriving and being deposited on the support and thatthe protective tape 20 has been broken so that the support is entraininguncovered adhesive 2 with it.

It is this situation which could cause a disaster downstream(considering the direction of arrow F1) of the assembly 600 and whichthe invention makes it possible to rule out.

To do this, the adhesive 2 which has already been applied to the supportand which might continue to arrive from the reservoir 1 via the tube 3and the distribution orifice 4 is made inoperative so that it has noeffect on the various components of a machine located downstream of theassembly 600.

According to a first embodiment, the adhesive 2 which has already beenapplied is lifted off, the verb “lift off” being adopted deliberately tosignify that the adhesive 2 has to be removed completely, firmly andimmediately, it being possible for the slightest spot of adhesive 2 notcovered with protective tape 20 to have extremely serious consequences.

In FIGS. 43 and 44, it can be seen that the lifting off consists insacrificing the corrugated cardboard support by cutting it, which isobviously much more advantageous than introducing uncovered long-actingadhesive 2 into a machine.

According to the variant embodiment of FIG. 43, the upper part of thesupport is removed, that is to say the sheet of paper 32 primitivelystuck to the sheet of corrugated paper 34, the latter itself being stuckto a lower sheet of paper 33.

It would be satisfactory to strictly only remove the adhesive 2 but,since the smallest fraction of adhesive 2 remains dangerous, it isillusory with the means currently available to hope to keep the supportintact while removing all the adhesive 2. It is more prudent, at theexpense of sacrificing a certain length of support, to cut it in thedirection of its height so that its lower cut fraction 34 b remainsstuck to the lower sheet 33 and continues on its normal course whereasits upper fraction 34 a remains stuck to the upper sheet 32 which bearsthe adhesive 2, these three secured elements: fraction 34 b, upper sheet32 and adhesive 2 are evacuated together so as to be eliminated. Arectangle M schematically shows the set of components, apparatuses andparts which make up the entire machine part located downstream of theassembly 600 for applying long-acting adhesive 2.

For this lifting-off operation, there is shown in FIG. 43 a safetydevice 1060, the essential element of which is a blade 1061 mounted topivot, as shown by arrow F15, on a horizontal axle 1062 between anactive position in which it cuts the corrugated cardboard support and awaiting position shown in dashed line in which it is away from thecourse of said support, which is the normal operating situation,implying correct laying of the protective tape 20.

The blade 1061 may be fixed or mobile, and is formed for example by arotating disk, the periphery of which is sharp so as to have highcutting effectiveness and, being arranged in an inclined plane, itserves as a ramp to the assembly 2-32-34 b which is directed towards atube 1063 associated with a suction mechanism (not shown) whichterminates at a receptacle 1064 used for the temporary storage of thewaste prior to elimination thereof.

In practice, the blade 1061 has to be provided with protection making itpossible to avoid an accident to the body due to its dangerous nature.

As soon as the photoelectric cells 1047 and 1048 are no longer masked bythe protective tape 20, the controller 1050 activates the alarm 1051 soas to urgently warn the staff monitoring the machine.

It is possible that the safety device 1060 is placed quite far from theassembly 600 for applying the protective tape 20 and/or that the speedof travel of the support gives the staff the time required to activatethe safety device 1060.

However, it is more advantageous to make this activation automatic, inwhich case the device 1060 has to be consequently equipped, which iswithin the capability of the person skilled in the art and which istherefore neither shown nor described here. The triggering member, whichmay be a circuit breaker, an electrovalve, etc. is actuated by thecontroller 1050 and the electrical connection 1052.

According to the variant embodiment of FIG. 44, where the same elementsas those in FIG. 43 bear the same references, the support is cutperpendicular to its faces 32 and 33, and right through.

To do this, the safety device 1060 comprises one or more rotating disks1065 having a cutting periphery and being mounted on at least one lever1066 which is mounted to pivot, as shown by arrow F16, on a horizontalaxle 1067 between an active position in which the lever 1066 is loweredand in which the disk or disks 1065 are driven in rotation in thedirection of arrow F17, passing through the entire thickness of thesupport, and a waiting position shown in dashed line in which the lowestpoint of the disks 1065 is located markedly above the support, theadhesive 2 and the protective tape 20.

With reference to the explanations given in relation to FIG. 43, it willbe understood that the safety device 1060 is set in operation manuallyor automatically by lowering the lever 1066 and setting the disks 1065in rotation as soon as the controller 1050 receives the signal from thephotoelectric cells 1047 and 1048.

If the bead of adhesive 2 is located close to a longitudinal edge of thesupport, it is sufficient if there is a single disk 1065 located at animaginary line of the support, parallel to this longitudinal edge andlocated on this side of it, for cutting a margin of the support that ismuch wider than the bead of adhesive 2, so as to remove with certaintythe entire width of this bead 2.

If the bead of adhesive 2 is far from the longitudinal edges of thesupport, two parallel disks 1065 are used so as to cut a strip, theedges of which are located on either side of the bead of adhesive 2,quite far from it, so as to remove with certainty the entire width ofthis bead 2.

When the invention is applied to a corrugator, it is possible totransversely juxtapose a number of devices for applying adhesive 2 andas many devices for applying protective tape 20 since the width of thestrip may be several meters whereas the articles that are to be cut fromthis strip are much narrower, which implies the application of severalparallel beads of adhesive 2 and, therefore, the application of as manyprotective tapes 20.

In this case, it is necessary to provide as many pairs of disks 1065 asthere are beads of adhesive 2, since it is obviously not possible toknow in advance on which line an incident will occur.

Regardless of whether it is a question of a margin or a strip or anumber of strips, they are all denoted by the reference 1014 and it canbe seen that they are, individually or together, sucked up into the tube1063 in order to end up at the receptacle 1064.

According to another embodiment of the invention, the sacrifice of thesupport already provided with adhesive 2 is avoided by placing onto thesupport a material element which goes beyond the protective tape 2 so asto neutralize its effects prior to introduction into the assembly M ofthis support bearing the uncovered adhesive 2.

In FIG. 45, in which the same elements as in FIGS. 43 and 44 bear thesame references, it can be seen that the machine is provided with asafety device 1070 which is formed in the same way as a device 600 forapplying protective tape 20. In other words, in the event of an incidentaffecting the device 600, the controller 1050 activates the alarm 1051and the staff, or an automatic mechanism controlled by the controller1050 via the line 52, sets the device 1070 in operation, said deviceacting as substitute for the faulty device 600.

For this purpose, the safety device 1070 is designed to deliver aprotective tape 1071 and comprises a reel 1072, a deposition mechanism1073 and a pressure roller 1074.

It would also be possible for the two assemblies 600 and 1070 to berigorously equal and to act as perfect substitutes for one another,which would have the advantage of guaranteeing continuous operation evenwhen one of the reels is empty, although this is not an incident in thestrict sense.

It is then necessary to have an alert mechanism or automaticsynchronization mechanism to ensure that an assembly 600 or 1070 entersinto operation as soon as the other, 1070 or 600, becomes unavailablefor a normal reason or on account of an operating incident.

However, the two devices 600 and 1070 being necessarily offsetlongitudinally, the adhesive 2 is not rigorously in the same physicalstate at the two points where it can receive the protective tape 20, sothat attention must be paid to the state of things, in particular byprecisely adjusting the viscosity and the siccativity of the adhesive 2,the application temperature, the speed of travel of the support andother parameters that are likely to affect correct application of theprotective tape 20-1071 to the adhesive 2.

It is also possible to lay an adhesive covering tape which is appliedcompletely to the adhesive 2 that has already been deposited, regardlessof the state of the latter, that is to say independently of its coveringtape retention power, said covering tape being fixed to the support andensuring isolation of the adhesive 2.

However, the entire length of the support thus protected cannot be usednormally and, in order to perfectly identify the zone of the support inquestion, the covering tape may be of a color that is very differentfrom that of the normal protective tape 20.

The devices 600 and 1070 are exactly aligned and positionedlongitudinally so that the tape 1071 is applied in time so that no partof adhesive 2, no matter how small, is not provided with protective tape20, if necessary by covering of the end of the tape 20 with the start ofthe tape 1071, as shown in the zone 1075.

Referring now to FIG. 46, another embodiment of the invention can beseen in which the material element which is placed on the support in theevent of an incident in the application of the protective tape 20 is achemical product.

Long-acting adhesives which currently exist are inactive or weaklyactive on silicones, for which reason the protective tape 20 is made ofpaper, at least one face of which is coated with silicone, or ofsynthetic material.

Thus, the tape 20 sticks slightly to the adhesive 2, especially when itis pressed by the roller 21 while the adhesive 2 is still quite hot, andcan be removed easily when a user subsequently wishes to use theadhesive 2, in particular to keep a container erect and/or to close acontainer, since this removal practically does not at all oppose thestrength while the adhesive 2 is fully active.

This is why, with the means currently known, the chemical product whichseems best suited to the implementation of the invention is a productfrom the silicone family, although this obviously does not exclude otherchemical products which could have the effect of completely neutralizingthe adhesive 2, it being recalled once more that even the slightest spotof active adhesive 2 is to be excluded.

For this reason, the use of a solvent for the adhesive 2 has been ruledout since its effect is both incomplete and slow, although this willperhaps not always be the case, in which case the invention could beapplied with such a product.

Two variants are shown in the same FIG. 46 of one and the same safetydevice 1080.

According to the first variant, which is the simplest variant, theactivation of the alarm 1051 warns the monitoring staff who manually usea portable canister 1081 containing a pressurized silicone-based product1082 and provided with a valve 1083, so that by acting on the valve1083, the product 1082 is sprayed onto the uncovered adhesive 2 by thestaff themselves who check de visu the end of the correctly appliedprotective tape 20 and the new arrival of protective tape once theincident has ended, this visual observation ensuring that all theadhesive 2 that had incorrectly been left uncovered has indeed beenneutralized by a layer of silicone 1082.

The part of the support which bears the adhesive 2 covered with sprayedsilicone 1082 cannot be used since it is no longer possible to removethe silicone-based product 1082 and to use the adhesive 2; however, thispart of the support that was affected by the incident can continue itscourse in the assembly M without causing any damage, which makes itpossible for the machine to continue operating without any loss in termsof production.

It goes without saying that the manual use of pressurized “sprays” 1081does not require any automatic control by the controller 1050 and thatthe alarm 1051 must be sufficient to alert the staff who are speciallytrained for this intervention.

The other variant consists in using a reservoir 1084 of greater capacitythan a simple pressurized spray 1081, one or more tubes 1085 and one ormore fixed ramps 1086 placed transversely to the support over a widthcorresponding to the zone or zones that is/are to receive adhesive 2.

The spraying of product 1082 is brought about in synchronism with thepoint where there is no longer any protective tape 20, either manuallyafter the alarm 1051 has been activated or automatically by thecontroller 1050 and the connection 1052 which, in particular, can bringabout the operation of electrovalves (not shown).

It is clear from the above description that the method according to theinvention may be incarnated in devices which are different butcomparable, the important thing being to neutralize the adhesive 2 whichhas already been applied to the support or which is continuing toarrive, in order to make it possible for the machines to operate ascontinuously as possible despite an incident of major importance.

The necessary precision with which the long-acting adhesive 2 is appliedin order to subsequently obtain effective fixing of the applicationsurface and the destination surface must be considered not only in termsof distance with respect to the support, by determining a referenceplane, but also in terms of the speed at which the protective tape 20 isapplied with respect to the support, since there is always a relativemovement between these two elements.

This is why it is possible to provide for the pressure roller 21 to bedriven by a motor, the speed of which is synchronized with that of thesupport, so that the protective tape 20 is driven positively at thedesired speed.

However, according to the invention, there is a release from theconstraints resulting from the inertia of the reel 22 on which theprotective tape 20 is stored.

This is because, although the problem of this inertia is alwaysimportant, it becomes crucial when the long-acting adhesive and theprotective tape have to be applied sequentially, that is to say tosuccessive panels 5, and even more so when there are a number ofsegments of adhesive on each panel 5 since it is necessary to constantlycause the adhesive 2 and protective tape 20 to be applied to eachsegment and to interrupt the entire operation between these segments andpanels, otherwise the adhesive would be spread onto the machine itselfand onto inappropriate places.

The mechanical problem is therefore the operation of the applicationmechanisms, which is alternating and non-continuous.

It will be understood that these difficulties become worse as theapplication speed increases, said speed being a major economic factorand a constant aim for obtaining competitive cost prices.

According to the invention, action is taken first of all on the drivingof the protective tape 20, as shown in a number of variants in FIGS. 47to 62, to which reference will now be made.

The pressure roller 21 is kinematically connected to drive means, shownschematically in FIGS. 47 to 54 by an electric motor 21 a, the operationof which is synchronized with the displacement of the panels 5 to whichthe adhesive 2 and the protective tape 20 is to be applied, so that theoperation of the roller 21 is connected on the one hand to the effectivepresence or absence of a panel 5 at the roller 21 and on the other handto the speed at which the panels 5 are driven.

However, it is also necessary that the roller 21 drives the protectivetape securely and precisely at the start of each segment and that thisdriving is interrupted between two successive segments.

To do this, the roller 21 has a central part 21 b of smaller diameterthan that of two side parts 21 c and 21 d, the half-difference of thediameters being slightly less than the thickness of the protective tape20.

The two side parts 21 c and 21 d are designed to be in contact with thepanels 5, bearing against their upper face, which allows a central spaceto exist between this upper face and the central part 21 b, the heightof which is slightly less than the thickness of the protective tape sothat the free end of the latter engaged in this space is driven byfriction on the one hand against the central part 21 b and against theupper face of the panel 5.

These dimensions are very small because, in practice, the central part21 b has a diameter of 25 millimeters and the side parts 21 c and 21 dhave a diameter of 25.02 millimeters, that is to say a difference indiameter of 2 tenths of a millimeter. For the sake of clarity of thedrawing, the differences in diameter have been markedly exaggerated soas to better illustrate the particular structure of the roller 21 andthe mode of operation thereof.

The side parts 21 c and 21 d each form a tread having a width of 7millimeters, and the central part 21 b forms a zone for pressing theprotective tape 20 having a width of 28 millimeters for a protectivetape 20 having a width of 25 millimeters.

In order to make the mode of operation of this device clearer, thevarious figures show distinct situations whereas in practice there is arapid chain of actions in which it is not possible to distinguish thesevarious phases. In particular, there must not be any case in which apanel 5 passes beyond the roller 21 without adhesive 2 and withoutprotective tape 20 (FIGS. 49 and 50) or without adhesive and withprotective tape 20 (FIGS. 51 and 52). These FIGS. 47 to 53 therefore donot necessarily show actual situations.

In FIGS. 47 and 48, the roller 21 is shown in the situation where thereis no panel 5 present and it can be seen that there is a space E1between the lower generatrix of the side parts 21 c and 21 d and theupper face of the conveyor 301 on which the panels 5 should be locatedin order to be driven.

This situation corresponds to the case where an interval between twosuccessive panels 5 is at the roller 21, so that the motor 21 a can bestopped. However, given that the roller 21 is not in contact with anyelement, it may continue to be driven by the motor 21 a, that is to sayit is then running idle.

In FIGS. 49 and 50, it can be seen that a panel 5 has arrived, driven bythe conveyor 301, and that the space E1 is entirely filled by the panel5 so that the treads 21 c and 21 d are in contact with the panel 5 andthe speed of rotation of the roller 21 has to be set so that itstangential speed is exactly equal to the linear speed of the panels 5,in which case their relative speed is zero.

From the very start of the manufacturing process, the free end of theprotective tape 20 has been engaged behind the roller 21, to the rightof the central part 21 b, and, since the difference in the diametersbetween the treads 21 c-21 d and the central part 21 b is only 2/10thsof a millimeter, the space into which the protective tape 20 isintroduced is 1/10th of a millimeter, which is slightly less than thethickness of said protective tape 20, for example 5/10ths of amillimeter.

Consequently, the central part 21 b of the roller 21 exerts a verticalpressure from top to bottom on the protective tape 20, taken between therotating roller 21 and the moving panel 5, the fortunate consequence ofwhich is to securely tow the protective tape 20 by overcoming anyresistance to advance to which it may be subjected on account of theapplication mechanism 600 and/or the reel 22.

Shown in FIG. 51 is the long-acting adhesive 2 arriving from theapplication head 6 via the orifice 4 but before it has reached theroller 21, which once again does not correspond to an actual situationbut is useful for breaking down the various movements.

Finally, FIGS. 53 and 54 correspond to reality, namely the applicationof the long-acting adhesive 2 and the protective tape 20 to a panel 5.

It can be seen that all the elements present are driven positively: thepanel 5 is driven by the conveyor 301, the adhesive 2 applied to thepanel 5 obviously follows it, and the protective tape 20 is driven bothby the panel 5 and by the roller 21.

However, as explained above, the panel 5—adhesive 2—protective tape 20assembly must be rolled so that the relatively thick bead of adhesive 2is to be spread laterally, at least partially.

Geometrically speaking, the space of 1/10th of a millimeter isintentionally too small to allow the bead of adhesive 2 and theprotective tape 20 to pass, but the roller 21 is allowed a smalllatitude of displacement in terms of height in the amplitude x visiblein FIGS. 53 and 54, that is to say that the roller 21 and its axle aremounted to move vertically, as has already been seen in FIGS. 1 and 22.

The top position of the roller 21 and of its axle can be rigidly fixedby a stop since it is necessary to calibrate as well as possible thetotal adhesive-protective tape thickness, but experience shows that anelastic vertical force exerted on the axle of the roller 21 is perfectlysuitable, which can be obtained by using a pneumatic ram to exert thisforce, the elasticity of the air being sufficient to allow bothsufficient displacement and permanent pressure of the roller 21.

FIG. 55 shows that the central part 21 b of the roller 21 may beprovided with reliefs, in particular knurling, so as to increase itsdrive coefficient with the protective tape 20.

FIG. 56 shows that the side parts forming treads 21 c and 21 d of theroller 21 may be provided with reliefs, in particular knurling, so as toincrease their drive coefficient with the upper face of the panels 5.

Of course, one and the same roller 21 may be provided with reliefs bothin its central part 21 b and in its side parts 21 c and 21 d.

The reliefs may be of various types, in particular burrs, when theroller 21 is to cooperate with the protective tape 20 and/or with theactual support not only by rolling and friction but also by penetrationinto the material forming the protective tape 20 or the support.

FIG. 57 shows a variant of the method of the invention in which theprotective tape 20 is wider than the bead of adhesive 2 after rolling,which makes it easier to remove the protective tape when it is desiredto expose the long-acting adhesive when fixing the application anddestination surfaces.

FIG. 58 shows a particular embodiment of the invention in which theprotective tape 20 is much wider than the bead of adhesive 2 afterrolling, in order that the side margins of this protective tape 20 whichgo beyond the edges of the bead of adhesive 2 can be inserted betweenthe support and the treads 21 c and 21 d, which are then advantageouslyknurled in order to increase the drive coefficient.

FIG. 59 shows the drive of the roller 21 by a transmission belt actingas a more complex application mechanism 600 which will now be describedwith reference to FIGS. 60 to 62.

The pressure roller 21 may be made of metal (in particular steel) butmay also be made of elastomer, in particular of the type having astructure comprising a peripheral tread and a solid central part, thisbeing made in a single piece with essentially radial, usually curvedtongues.

The diameter of the roller 21 may be more or less great, the dimensionsgiven here by way of example not being in any way limiting in nature.

It will be understood that the actual problem that has to be solved isthat of faultlessly applying protective tape 20, no tolerance beingpossible for slipping, swerving or absence of the protective taperelative to the already applied adhesive 2.

However, this adhesive 2 is applied to the support and there is nopossibility of displacement of said adhesive 2 relative to the support.Consequently, the piloting of the protective tape 20 may be carried outwith reference to the support rather than with reference to theadhesive, since it is easier and more reliable to refer to the supportwhich is a solid material element, the position of which in space iseasily determined or determinable, even individually panel 5 by panel 5.

This is why the invention provides a solution that is slightly differentfrom that described above which, it should be recalled, consists insynchronizing the application of the protective tape 20 with thedisplacement of the panels 5.

This other solution consists in securing to one another the support onthe one hand and the protective tape 20 on the other.

To do this, use may be made of an immediate-action glue which isdeposited in a small amount (for example a single spot) on the support,in a small zone located close to the point where the protective tape 20is to come alongside, that is to say close to its free end. This smallzone is located close to the transverse edge upstream of each panel 5.

The immediate-action glue deposited on the support may be replaced witha product having affinity with the already deposited adhesive 2, inorder to securely fix the protective tape 20 to the adhesive 2 despitethe low voluntary adhesion of the silicone-coated face.

In order to implement this method, the machine must be provided with areservoir and with a tube ending at an outlet orifice forming a device(not shown) for delivering product, immediate-action glue or the like,the practical design of which is within the capability of the personskilled in the art.

When the machine comprises a deposition station for depositing adhesive2 and a deposition station for depositing protective tape 20, saiddeposition stations being offset from upstream to downstream withrespect to the displacement of the panels 5, the outlet nozzle of thedevice for delivering product is located between these two stations.

Another solution consists in using the property of the protective tape20 of having a face that is very insensitive to the adhesive 2, inparticular because this face is coated with silicone, and an oppositeface which is, on the other hand, sensitive to the adhesive 2, inparticular because it is not coated with silicone.

This structure is found in particular with protective tapes made ofpaper that has been coated with silicone on just one side.

In order to secure the protective tape 20, it is folded transverselyclose to its free end so as to fold this protective tape 20 back onitself a little in order that, close to its free end, and there alone,the protective tape 20 presents the already deposited adhesive 2 withits face that is sensitive to retention of the latter, by virtue ofwhich the positive fixing of the protective tape 20 to the adhesive 2already deposited on the support is obtained.

Securing the protective tape 20 to the support, directly or via theadhesive 2, has the advantage of anchoring this protective tape 20,making it possible to tow it at the speed of travel of the panels 5despite the great force that has to be developed in order to extract itturn by turn from the reel 22, even in rapid sequential operation,subjected to frequent jerks.

In order to synchronize the linear speed of the support and thetangential speed of the roller 21, use may be made of the motor 21 a,although it is necessary to have a relatively complex and delicatepiloting assembly which is a source of breakdown and which requires aminimum of monitoring and maintenance that can be saved by virtue of themethod described below.

The application mechanism 600 comprises a mobile rig, the base elementof which is a board 2000 mounted to pivot parallel to its plane andconnected to the pneumatic ram 80 designed to make it pivot in twoopposite directions, for a reason which will be explained below.

Mounted to rotate on the board 2000 are a number of rollers, includingone drive roller 2001 designed to enter into contact with the successivepanels 5 and to maintain this contact over the entire length of eachpanel 5. Thus, the linear displacement of the panels 5 by the conveyorof the machine (not visible in FIGS. 60 to 62) has the consequence ofplacing the drive roller 2001 in rotation.

A movement transmission member, in this case a belt 2002 which may benotched, is engaged in a groove of the drive roller 2001 and in a grooveof a guide roller 2003 which at the same time forms the axis of pivotingof the board 2000.

A second belt 2006 engaged in another groove of the same guide roller2003 is engaged with a groove of the pressure roller 21 (see also FIG.59), so that the setting in rotation of the drive roller 2001 has theconsequence of setting the pressure roller 21 in rotation in the samedirection.

The free strand of the protective tape 20 passes over tensioning andguide rollers 2007 and is engaged below the central part 21 b of theroller 21.

In FIG. 60, a panel 5 is present and the drive roller 2001 is rotating,the ram 80 has been supplied with compressed air so as to bring aboutthe extension of its rod which has made the board 2000 pivot at anangle, the apex of which is in the axis of the guide roller 2003, asshown by arrow F18. The pressure roller 21 is not only also rotating butis moreover lowered until it is in contact with the panel 5 againstwhich it exerts a pressure through the protective tape 20 and the beadof adhesive 2, as described in detail with reference to FIGS. 47 to 54.

In FIG. 61, it can be seen that at the pressure roller 21 there is aninterval between two successive panels 5, and the supply to the ram 80has been reversed so as to make the board 2000 pivot in the oppositedirection, at the same angle, as shown by arrow F19, in the direction ofraising the pressure roller 21.

It will be noted that the pivoting by a few degrees, in one directionand then in the opposite direction, of the guide roller 2003 has noeffect on the transmission of the rotation of the drive roller 2001.

The latter being in contact with the panels 5 downstream of the assembly500 for applying the adhesive 2, it is necessary for it to be positionedbeside the bead of adhesive 2 as seen in FIG. 62 which also shows that,on account of the necessary alignments for the belts 2002 and 2006, thedrive roller 2001 has a shaft 2008 of smaller diameter than that of theactual active part that is in contact with the panels 5, in order to belocated markedly above the upper level of the bead of adhesive 2.

This mechanism 600 is extremely effective and very simple since thespeed of the engaged rollers is always strictly equal to the linearspeed of the panels 5, without any possible variation because they allhave exactly the same diameter.

The device which has just been described is one example of motorization,which differs from the use of the electric motor 21 a but which ends upgiving the same result which is to move the application roller 21.

Shown in FIG. 63 is one embodiment which makes it possible to suppressthe resistance to traction of the protective tape 20, due to the inertiaof the reel 22.

This provision is particularly important for the simultaneous sequentialapplication of long-acting adhesive 2 and of protective tape 20, that isto say to panels 5 which are separated by intervals which require thatthe application be started and stopped alternately at a rhythm whichincreases as the speed of the machine quickens to produce more. If, bycontrast, the application is carried out continuously onto a strip ofindefinite length, the problem of the traction of the protective tape 20is less difficult because once it has been started at the start of thecycle by effective fixing of the end of the protective tape 20, thelatter unwinds continuously from the reel and the problem of this typeof installation is only that of changing the empty reel for a full reel.

It can be seen in FIG. 63 that an intermediate stock of unwoundprotective tape is created, which is in the form of long free loops,that is to say that the operation of unwinding from the reel and theapplication operation are dissociated.

The free strand of the protective tape 20 is engaged between two rollersthat are associated to form a pair 2010, at least one of which iskinematically connected to a motor 2011 so as to drive the protectivetape 20 to extract itself turn by turn from the reel 22.

After having been towed by the pair of rollers 2010, the free strand ofthe protective tape 20 is engaged in the inlet 2012 of a parallelepipedreceptacle 2013 that is provided, opposite the inlet 2012, with anoutlet 2014 via which the free strand of the protective tape 20 isextracted from the receptacle 2013, after which it is conducted bytensioning and guide rollers 2007 to the application mechanism 600described above.

Inside the receptacle 2013, the protective tape 20 accumulates randomly,that is to say without tight winding, in stacked wide folds, alternatelyto the left and to the right, without any attachment so as not to opposeany resistance to traction of the protective tape 20 out of thereceptacle 2013 via the outlet 2014.

According to the method of applying the protective tape 20 to thesupport provided with adhesive 2, there is provided between the outlet2014 and the deposition assembly traction motor means where, as shown,this traction at the outlet of the receptacle 2013 is obtained by thedeposition assembly itself, during the pinching action exerted by thepressure roller 21.

When a certain length of protective tape 20 has been extracted from thereceptacle 2013, an equivalent length is introduced into the latter viathe inlet 2012 in order that there remains in the receptacle 2013 alength of protective tape 20 that is essentially constant.

This introduction of protective tape 20 into the receptacle 2013 via theinlet 2012 is obtained by operating the pair of rollers 2010 by means ofthe motor 2011 and the power of this motor 2011 is calculated so that itsubstantially exceeds the resistance to pivoting of the reel 22.

It is thus possible to associate this reel 22 with a motor 2015 forsetting in rotation, said motor 2015 being synchronized with the motor2011 so that they operate in a coordinated manner, providing inparticular the tension of the protective tape 20 between the reel 22 andthe inlet 2012.

Another solution consists in providing the reel 22 with a brakingmechanism 2016 which acts on its rotation axle, which mechanism may be,for example, an electromagnetic brake which functions intermittently tobrake the reel 22 when the pair of rollers 2010 is stopped and torelease the reel 22 when the motor 2011 is operated so as to drive thepair of rollers 2010.

It is thus possible to make the braking mechanism 2016 operateconstantly but at a low braking value so that the traction force on theprotective tape 20 is greater than the braking force, which makes itpossible to unwind the turns from the reel 22 while ensuring the tensionof the protective tape 20 between said reel 22 and the pair of rollers2010.

In order to prevent any accident that could result from the reel 22being released while the pair of rollers 2010 are not in a situationwhere they are driving the protective tape 20, there is a member formonitoring the tension of this protective tape 20.

In this case, this member is a pilot roller 2017 which is positionedsuch that the protective tape 20 stretched between the reel 22 and theinlet 2012 is necessarily in contact with it.

This pilot roller 2017 is associated with a control mechanism (notshown) which causes either activation of the braking mechanism 2016 oroperation of the motor 2011 so as to gather up the slack of theprotective tape 20 shown in dashed line in FIG. 63.

The slack of the protective tape 20 has the effect of breaking thecontact between the protective tape 20 and the pilot roller 2017, andthis event is detected:

-   -   either by ascertaining that the pilot roller 2017 is no longer        driven in rotation whereas, at the same time, the reel 22 is        released and the pair of rollers 2010 is stopped,    -   or by ascertaining that a mobile support (not shown) on which        the pilot roller 2017 is mounted to rotate has changed position.

The receptacle 2013 has six faces, two large faces and four small faces,the latter having a width such that the two large faces are separatedfrom one another over a distance that is slightly greater than the widthof the protective tape 20, so that the latter can remain in thereceptacle 2013 without substantially rubbing against its walls.

In order that the person operating the machine can judge de visu whetherthe receptacle 2013 does indeed contain a sufficient length ofprotective tape 20, the walls of this receptacle 2013, and in particularat least one of its two large faces, are transparent.

However, this evaluation by the person operating the machine is notsufficient since it is absolutely necessary to ensure continuousoperation of the deposition assembly 600, so that it is necessary toprovide automatic monitoring means.

In this case, the choice has been made to measure the weight of thereceptacle 2013 containing the desired length of protective tape 20, thereceptacle 2013 being placed on a support 2020 which is mounted pivotingon an axle 2021 located close to one of its ends, and which is providedwith a suitably preloaded return spring 2022. Close to the end of thesupport 2020 opposite the first end there is a presence detector 2023 ofany known type, in order that the latter can detect the movement of thereceptacle 2013 as soon as the action of the return spring 2022 becomesgreater than the action of the weight of the receptacle 2013.

As soon as this event occurs, this means that the receptacle 2013 hasbecome lighter, that is to say that a length of protective tape 20 hasbeen extracted via the outlet 2014 and that it is necessary to restockthe receptacle 2013 by introducing into the latter a length ofprotective tape 20 that is equivalent to that which has exited. Thedetector 2023 then controls the action of the pair of rollers 2010 inorder to introduce this missing length of protective tape and controlsthe stopping of this same pair 2010 as soon as the receptacle 2013 hasregained its normal weight, this being detected by the detector 2023.

This mode of operation ensures the continuity of supply of protectivetape 20 and guarantees that the correct length of this protective tape20 is indeed present in the receptacle 2013.

It will be understood that the part of the protec tape 20 which islocated in the receptacle 2013 is entirely free and does not oppose anyresistance to its almost instantaneous traction and to its immediatestopping, which operations are repeated all the more often as theoperating speed of the machine increases.

FIG. 64 shows another embodiment of the invention which also makesprovision for suppressing the resistance to traction of the protectivetape 20.

With the embodiment of FIG. 63, the inertia is suppressed by virtue ofthe protective tape 20 being untensioned as it exits the reel 22. Inthis case, the method consists in cutting the free end of the protectivetape 20, which suppresses any direct connection between the tractionmember (the roller 21) and the reel 22.

As it exits the reel 22, the protective tape 20 passes over a guideroller 2007 before arriving at a precutting assembly 2100.

This assembly 2100 comprises a base 2101 on which there are rotatablymounted four rollers which are grouped into two pairs 2102 and 2103 andof which one of each pair is kinematically connected to a motor2104-2105.

The two pairs of rollers 2102 and 2103 are arranged on either side of acentral cutting mechanism 2106 which consists of a cutting cylinder 2107kinematically connected to a motor 2108 and of a countercylinder 2109.

Fixed guides 2110 and 2111 are provided on either side of the centralmechanism 2106 between the latter and the two pairs of rollers 2102 and2103, and a fixed guide 2112 is provided between the pair of rollers2103 and the application assembly which includes the roller 21.

After the guide roller 2007, the free end of the protective tape 20 isengaged between the two rollers of the pair 2102, then in the fixedguide 2110, then between the cutting cylinder 2107 and thecountercylinder 2109, then in the fixed guide 2111, then between the tworollers of the pair 2103, then in the fixed guide 2112 and finally belowthe central part 21 b of the roller 21.

In order to ensure the tension of the protective tape 20 as it exits thereel 22, the latter is advantageously provided with a rotating mechanism2015 or braking mechanism 2016 operating as explained with reference toFIG. 63, that is to say in synchronism with the traction members whichin this case are the rollers of the pair 2102.

When the machine is started, the format of the panels 5 which will beused is exactly known, and the length of the segments of protective tape20 that have to be applied is thus known very precisely.

The rate at which the machine operates is also known, so that the speedat which the protective tape 20 is to travel from the reel 22 to thedeposition assembly is known.

Based on these parameters, the speed of rotation of the cutting cylinder2107 is set so as to pass from the position which it occupiesimmediately after cutting to that which it must occupy just before a newcutting operation.

The mode of operation of this cutting assembly 2100 is as follows:

The protective tape 20 has been engaged as explained above.

At a given moment, the first cutting takes place by almost instantaneousrotation of the cutting cylinder 2107, which creates a segment which hastwo free ends and which extends downstream of the cutting mechanism 2106and upstream of the deposition assembly, engaged between the two rollersof the pair 2103 which displace it until it is pinched by the roller 21,which operates as has already been described.

Thus, when the protective tape 20 is applied to the moving panel 5, itis in the form of a segment that has already been cut, which no longerforms part of the turns of the reel 22 and which, having aninsignificant weight, does not oppose any resistance to being placed bythe roller 21, all the more so since the segment has a length that issufficient to still be engaged between the two rollers of the pair 2103which aid its displacement.

Depending on the length of each segment, the cutting cylinder 2107 is inaction more or less often, this data being easily maintained throughoutthe production of identical products. It can moreover easily be adjusteddepending on requirements.

It will nevertheless be noted that the minimum permissible length L2 ofa segment is essentially equal to the distance D2 which separates theaxles of the rollers of the pair 2103 and the axle of the roller 21since a shorter segment would no longer be engaged between the rollersof the pair 2103 and nor would it be pinched by the roller 21, so thatit would be abandoned without the fixed guide 2112 and would cause thesegments behind it to jam.

The method just described differs from a method which has been known fora long time and which consists in applying short or very short segmentsof protective tape, in particular to envelopes, and which is implementedin four phases:

-   -   the protective tape is cut so as to create a free segment,    -   this segment is grasped and kept immobile, stretched in a        straight manner,    -   the segment is applied in its place,    -   the segment is released.

It will be noted that there is no prior adjustable measurement becausethe cutting of the protective tape is carried out by means of a circulartemplate of given diameter, an arc of which gives the length of thesegment. For a different length, another circular template must be used.

It is clear from the above description that the invention allows veryprecise application of a long-acting adhesive, which is eitherpre-existing on a prefabricated support of the transfer tape type orapplied directly to a support immediately upstream of the application ofa protective tape, even when the support is not perfectly flat and even,so that this long-acting adhesive can be used a long time after it hasbeen applied, with the same precision, despite random manual operations,by virtue of operations carried out in the factory on a machine.

The quality of the product obtained is accompanied by an additionaladvantage which is the high speed possible for the industrial machinesused, both in continuous operation, of the corrugator type, and indiscontinuous (or sequential) operation, of the folding-collectingmachine type.

1. A device for depositing an adhesive product onto a support, whereinthe adhesive product includes a long-acting adhesive and a removableprotective tape for delayed use of the adhesive, said device comprising:a protective tape supply; an adhesive supply; a deposition stationcoupled to said supplies and configured to dispense the protective tapeand the adhesive, said deposition station comprising: means fordelivering the adhesive to the support; means for delivering theprotective tape to the support; at least one substantially flat rigidpart forming a reference plane located substantially parallel to andoffset a predetermined distance from a plane formed by an applicationsurface of the support upon which in which adhesive and protective tapeare delivered; a member configured to exert a force in a directionsubstantially transverse to the surface of the support that receives theadhesive and protective tape thereon, said member comprising a moveablesupport-engaging active part arranged such that said active part keepssaid application surface constantly pressed against said reference planeformed on said rigid part; and means for placing the support intorelative movement with said deposition station.
 2. The device of claim1, wherein said rigid part and said member are configured as an assemblycomprising a plate arranged transversely to said rigid part over theentire width of the course of the support, and of which one face thatforms the active part is located beyond the plane in which one of thetwo faces of the support is to be located so that the strip is subjectedover its entire width to a transverse force due to assembly.
 3. Thedevice of claim 1, wherein said rigid part and said member are arrangedon opposing sides of the support that passes therebetween.
 4. The deviceof claim 3, wherein said rigid part comprises an immobile stop and themember comprises a lever that is stressed elastically in the directionof the stop, wherein said active part is formed by a roller mountedidling at the end of a lever on said member.
 5. The device of claim 4,wherein said lever is connected to a base that is mounted so as to beable to move between a first active position and a second withdrawnposition, wherein during said first position, said lever is close enoughto the course of the support for said roller to be in contact with oneof the faces of said support, and during said second position, saidlever is spaced away from its active position.
 6. The device of claim 5,wherein said base is associated with an automatic control mechanism thatis designed to place said base either in said active position or in saidwithdrawn position, depending on whether there is a support or aninterval between two successive supports opposite said roller.
 7. Thedevice of claim 4, wherein said stop is located at the end of a head forapplying adhesive at which there terminates a tube for supplying liquidadhesive from the adhesive supply, said head being affanged close tosaid plane in which one of the faces of the support is to be located. 8.The device of claim 1, wherein a destination surface on the supportsdefines a surface configured to engage the application surface, thedestination surface being insufficiently able to retain said long-actingadhesive when the destination and application surfaces are broughttogether, said device further comprises means for making at least thedestination surface undergo, before it joins the adhesive, at least oneof a physical and chemical treatment capable of improving the adhesionthrough treatment to improve retention of the adhesive.
 9. The device ofclaim 8, wherein said device is equipped with a rough surface which isto be in contact with the support so as to remove from it a surfacelayer without dissociation of the fibers.
 10. The device of claim 8,wherein said device is equipped with a suction mechanism configured toremove waste created by said rough surface.
 11. The device of claim 8,wherein said device is equipped with a heat treatment assembly which isto receive at least part of the tape immediately before it is applied tothe support.
 12. The device of claim 8, further comprising an electrictreatment assembly configured to subject at least one of the destinationand application surfaces to a high-frequency electric field prior tojoining of the surfaces.
 13. The device of claim 12, wherein saidelectric treatment assembly comprises two electrodes that are togenerate between them a high-frequency electric field and between whichat least one of the surfaces must pass.
 14. The device of claim 12,further comprising means for printing the tape, said means being locateddownstream of said electric treatment assembly in a direction ofrelative displacement between the support and the printing means. 15.The device of claim 8, further comprising: an inlet feeder for receivingthe support that is in the form of separate stacked, cut panels stackedon said feeder; a guideway for sequentially guiding the panels; and atransporter terminating in an outlet stacker and cooperative with saidguideway to receive the panels, wherein the tape and adhesive suppliescomprise a distributor for distributing the tape and adhesive, eitheralone or already associated in the form of a prefabricated assemblycomprising a base, a mechanism for cutting the tape in a mannercoordinated with the displacement of the panels so that the tape is cutadjacent opposing transverse ends of each panel, and wherein said meansfor applying said at least one of a physical and chemical treatment isconfigured to apply treatment either to the support alone or to both thesupport and the tape.
 16. The device of claim 8, further comprising: aninlet feeder for receiving the support that is in the form of separatestacked, cut panels; a guideway for sequentially guiding the panels; atransporter terminating in an outlet stacker and cooperative with saidguideway to receive the panels; and a distributor for distributing thetape and the adhesive, wherein said means for delivering the tape isconfigured to apply the tape in segments having a length that is nogreater than that of each panel, and comprises a mechanism for cuttingthe tape which is coordinated with the application mechanism for thepurpose of cutting the tape into segments that are each located insidethe contour of each panel, and wherein said means for applying said atleast one of a physical and chemical treatment is configured to applytreatment either to the support alone or to both the support and thetape.
 17. The device of claim 8, further comprising a corrugatorcomprising: an assembly for forming the support from reels of paper; aplurality of kinematic members for constantly or intermittently moving acontinuous strip formed by the joined rolls; a guideway for guiding thecontinuous strip; an assembly for cutting of the continuous strip so asto create independent sheets; and at least one stacker for stacking theindependent sheets, said corrugator configured to cooperate with theoperation of said device such that the adhesive is applied separately tosaid support, after which the tape is applied and at least onedistributor for distributing the tape to the adhesive, and wherein saidmeans for applying said at least one of a physical and chemicaltreatment is configured to apply treatment either to the support aloneor to both the support and the tape.
 18. The device of claim 17, whereinsaid distributor and said means for applying a treatment are locatedvertically above the continuous strip such that the adhesive and thetape are applied to an upward-facing surface of the continuous strip.19. The device of claim 17, wherein said distributor and means forapplying a treatment are located vertically below the continuous stripsuch that the adhesive and the tape are applied to an upward-facingsurface of the continuous strip.
 20. The device of claim 1, wherein saidmeans for delivering the adhesive to the support comprises an orifice,further wherein said means for delivering the tape comprises members forstoring and unwinding the tape and a mechanism for applying the tape tothe support such that the tape is at least partly on the adhesive,wherein said mechanism is arranged downstream of the orifice andincludes at least one detector for detecting the presence of the tapeand at least one sensitive element located downstream of the orifice andwhich is connected to an alarm and adhesive disabling mechanism.
 21. Thedevice of claim 20, further comprising an adhesive removing mechanismcomprising at least one blade that can move between a waiting positionin which it is located away from the support, and an active position inwhich it is situated beyond the plane of the support on which theadhesive has already been applied.
 22. The device of claim 20, furthercomprising an adhesive removing mechanism comprising at least onecutting element that can move between a waiting position in which thecutting element is located away from the support and a position in whichthe cutting element passes through the thickness of the support.
 23. Thedevice of claim 20, further comprising at least one pump and a suctionapparatus configured to remove waste from the continuous strip.
 24. Thedevice of claim 20, further comprising a distributor for distributing amaterial over the adhesive present on the support.
 25. The device ofclaim 24, wherein said distributor comprises at least one reel forstoring a reel of tape and a mechanism for delivering the support andapplying the tape to the support.
 26. The device of claim 24, whereinsaid distributor for distributing a material comprises a sprayer. 27.The device of claim 26, wherein said distributor comprises a portablecanister with valve, said canister configured to contain a pressurizedpropellant gas.
 28. The device of claim 26, wherein the distributor isfixed and comprises: at least one of a nozzle or with a spraying ramp;at least one tube connected to said at least one nozzle or sprayingramp; and an electrovalve configured to selective open said at least onenozzle or spraying ramp.
 29. The device of claim 1, wherein saiddeposition station further comprises: a distributor having one or moredistribution orifices; a distributor for distributing tape having atleast one support for a reel of tape, means for unwinding and guiding afree strand of the tape and an applicator mechanism; means forpositively driving the free strand of the tape and a mechanism forcontrolling the driving speed so that, just before the tape comesalongside adhesive already applied to the support, the linear speed ofthe free strand of the tape is equal to the linear speed of the relativemovement between the support and the deposition station; a calendarformed of two rotating rollers disposed on either side of the plane inwhich the support equipped with the tape is to extend; and an adjustablespacing located between said rollers such that the support, the bead ofadhesive and the tape are engaged to one another in said spacing so asto calendar the bead of malleable adhesive located between the tape andthe support, both having a thickness that is not substantially modifiedby the calendaring, so that the bead of adhesive is laterally spreadthat its face located against the tape forms in a single plane extendingabove the highest raised point of the application surface.
 30. Thedevice of claim 29, further comprising an assembly for applying to thesupport at least one of an immediate-action glue, a solvent and avarnish, said assembly comprising a reservoir and at least one outletnozzle fluidly connected to said reservoir such that the support canreceive the at least one of an immediate-action glue, solvent andvarnish stored therein.
 31. The device of claim 30, wherein said meansfor delivering adhesive and tape are offset in the direction of movementof the support such that said adhesive delivering means is upstream ofsaid tape delivering means.
 32. The device of claim 29, furthercomprising a pressure roller situated adjacent where the tape is to comealongside the support adhesive deposited thereon such that said pressureroller exerts a pressure on the support through the tape and theadhesive.
 33. The device of claim 32, wherein the pressure roller iskinematically connected to means for setting in rotation.
 34. The deviceof claim 33, wherein the means for setting the pressure roller inrotation comprises an axle-mounted drive roller that is in contact withthe moving support so that, by tangential friction, the linear movementof the support can be transmitted to said drive roller, which receivesat least one transmission member connected to the pressure roller. 35.The device of claim 34, wherein the pressure roller has a central partof smaller diameter than that of two side parts.
 36. The device of claim35, wherein said side parts are configured to engage the support withdirect contact.
 37. The device of claim 35, wherein said side parts areconfigured to engage the tape located between said side parts and thesupport.
 38. The device of claim 35, wherein the side parts have anon-smooth surface.
 39. The device of claim 35, wherein thehalf-difference of the diameters of said central part and said sideparts is less than the thickness of the tape so as to exert on thelatter a driving traction between the moving support and the rotatingcentral part.
 40. The device of claim 35, wherein the half-difference ofthe diameters of said central part and said side parts is less than thetotal thickness of the tape and of the bead of adhesive previouslydeposited on the support, so as to determine by at least one ofcalendaring or rolling the thickness of said bead of adhesive.
 41. Thedevice of claim 32, wherein said pressure roller is mounted to rotate ona mobile rig comprising control means configured such that said pressureroller can be placed in one of two extreme positions including a firstremote position in which said pressure roller is away from the supportand a second active position in which said pressure roller is in contactwith the support.
 42. The device of claim 41, wherein said mobile rig isconnected to a pneumatic control ram so that the thrust of said ram onsaid mobile rig is elastic.
 43. The device of claim 29, furthercomprising means for fixing the protective tape to the support so as tosecure them independently of the adhesive deposited on the support. 44.The device of claim 43, wherein the fixing means comprises a distributorfor distributing immediate-action glue.
 45. The device of claim 43,wherein the fixing means comprises a mechanism for cutting andtransversely folding the tape, the latter including folding a length ofthe tape from a free end so that in the folded part, a face of the tapethat is relatively less sensitive to the adhesive is folded back onitself and so that the opposite face that is relatively more sensitiveto the adhesive has a certain length on the same side of the tape as theface that is relatively less sensitive to the adhesive.
 46. The deviceof claim 1, further comprising: a receptacle having a passage, one ofwhich is an inlet in which a free strand of the tape coming from astorage reel is to be engaged and the other of which forms an outletthrough which the free strand of the tape is to pass; drive meansprovided to move and guide the tape from said storage reel to an inletof said receptacle and from an outlet of said receptacle to saiddeposition station, said drive means coordinated so as to conduct fromsaid storage reel to said inlet a length of tape that is substantiallyequal to that which is conducted from said outlet of said receptacle tosaid deposition station so that there is constantly in said receptacle asubstantial length of tape in a substantially slack state butessentially aligned in terms of width by virtue of the two large facesof said receptacle.
 47. The device of claim 46, wherein said drive meanscomprise a pair of rollers at least one of which is kinematicallyconnected to a motor and which is located between said storage reel andsaid inlet of said receptacle.
 48. The device of claim 47, wherein saiddrive means are further comprises a measuring instrument to determinethe length of tape present in said receptacle and which controls theoperation of said rollers so that the length driven towards said inletis essentially equal to the length driven from said outlet.
 49. Thedevice of claim 47, wherein said storage reel is mounted to rotate on anaxle and is cooperative with a braking mechanism.
 50. The device ofclaim 48, wherein said drive means further comprises a pilot rolleragainst which there bears the part of the tape located between saidstorage reel and said inlet of said receptacle when the tape is taut,said pilot roller in functional connection with said braking mechanismso that the latter is neutralized when the tape bears against said pilotroller and is made to have a braking action on said storage reel as soonas the tape is not taut and no longer bears against said pilot roller.51. The device of claim 46, wherein said storage reel is mounted torotate on an axle and is kinematically connected to a motor.
 52. Thedevice of claim 51, wherein said pilot roller is in functionalconnection with said motor so that motor speed is controlled when thetape bears against said pilot roller and is stopped as soon as the tapeis not taut and no longer bears against said pilot roller.
 53. Thedevice of claim 49, wherein said braking mechanism of said storage reelreleases upon application of said driving and re-release upon stoppageof driving.
 54. The device of claim 1, wherein said device is configuredto separately apply the adhesive and tape such that said tape supplycomprises a reserve comprising a reel, a mechanism located between thereel and the deposition station, said mechanism for cutting the tapeinto successive segments, a measuring device for measuring the length ofthe application surface of the support which is to receive the adhesiveand at least a segment of the tape, said mechanism for cutting and saidmeasuring device cooperative so as to consequently cut the segment tothe desired length before it is entirely placed on the support so thatit is separated from the turns of the reel.
 55. The device of claim 54,further comprising drive means for moving and guiding the tape from thereel to the cutting mechanism, said cutting mechanism comprising acutting member that can move between a withdrawn position in which it isaway from the course of the tape and an active position in which it ismomentarily on this course, said cutting member secured to a mobileelement such that the speed of displacement of said cutting mechanismfrom the active position of cutting one segment to that of the followingsegment is synchronized with the means for placing in relative movementthe deposition station and the support, the distance which existsbetween the cutting mechanism and the deposition station being smallerthan the length of the shortest permissible segment.
 56. The device ofclaim 55, wherein said drive means comprises two pairs of rollers, atleast one of each pair being kinematically connected to a motor, one ofthese two pairs being located between the reserve of tape and the inletof the cutting mechanism, and the other being located between saidoutlet of said cutting mechanism and said deposition station.
 57. Thedevice of claim 55, further comprising a pressure roller locatedadjacent the spot where the tape is to come alongside the support andthe bead of adhesive deposited thereon, the distance which existsbetween said pair of rollers located between the outlet of the cuttingmechanism and the pressure roller is smaller than the length of theshortest permissible segment.
 58. The device of claim 1, wherein saidmeans for delivering the adhesive and said means for delivering theprotective tape are configured to sequentially place the adhesive ontothe support prior to the protective tape.
 59. A device for depositing anadhesive product onto a support, wherein the adhesive product includes along-acting adhesive and a removable protective tape for delayed use ofthe adhesive, said device comprising: a protective tape supply; anadhesive supply; a deposition station coupled to said supplies andconfigured to dispense the protective tape and the adhesive, saiddeposition station comprising: means for delivering the adhesive to thesupport; means for delivering the protective tape to the support; atleast one substantially flat rigid part forming a reference planelocated substantially parallel to and offset a predetermined distancefrom a plane formed by an application surface of the support upon whichin which adhesive and protective tape are delivered; a member configuredto exert a force in a direction substantially transverse to the surfaceof the support that receives the adhesive and protective tape thereon,said member comprising a moveable support-engaging active part arrangedsuch that said active part keeps said application surface constantlypressed against said reference plane formed on said rigid part; andmeans for placing the support into relative movement with saiddeposition station, and a receptacle having a passage, one of which isan inlet in which a free strand of the tape coming from a storage reelis to be engaged and the other of which forms an outlet through whichthe free strand of the tape is to pass; drive means provided to move andguide the tape from said storage reel to an inlet of said receptacle andfrom an outlet of said receptacle to said deposition station, said drivemeans coordinated so as to conduct from said storage reel to said inleta length of tape that is substantially equal to that which is conductedfrom said outlet of said receptacle to said deposition station so thatthere is constantly in said receptacle a substantial length of tape in asubstantially slack state but essentially aligned in terms of width byvirtue of the two large faces of said receptacle.